SherWeb

What SherWeb does

SherWeb is a privately held cloud marketplace distributor headquartered in Sherbrooke, Quebec, founded in 1998 by brothers Peter and Matthew Cassar. The company operates a three-tier channel program (White-label, Co-branded, Advisor) serving more than 7,500 Managed Service Providers (MSPs) across Canada, the United States, Ireland, and the United Kingdom, which collectively serve over 100,000 organizations. SherWeb's core proposition is aggregating Microsoft cloud licenses (Microsoft 365, Azure, Dynamics 365), security vendors (SentinelOne, Huntress, Check Point, Bitdefender, Keeper, etc.), backup/continuity (Veeam, Keepit, Wasabi, Commvault), and productivity tools into a single procurement, provisioning, and billing platform, augmented by white-label professional services.

The underlying technology stack includes Sherweb Marketplace, the Cumulus partner platform (unified billing, provisioning, and license management with MFA and Microsoft Entra ID integration), and the Self-Service Portal (a Progressive Web App storefront for MSP end-clients with SSO and ConnectWise ticketing integration). SherWeb holds all six Microsoft Solutions Partner designations, carries 195+ Microsoft certifications, and is one of the first partners to earn Microsoft's Support Services designation. The company built native integrations with major PSA/RMM tools (ConnectWise, Autotask, HaloPSA, Kaseya BMS, Rewst, QuickBooks, CIPP, Pia), and was the first cloud solution provider to natively integrate with HaloPSA. Office Protect provides proprietary managed detection and response for Microsoft 365 tenants.

SherWeb monetizes through marketplace distribution (wholesale-to-resale spread on cloud licenses), recurring subscriptions (Microsoft 365, Azure, security), transaction fees on third-party vendor products, professional services (white-label helpdesk, NOC, consulting), managed services (Office Protect MDR, NOC), and an Advisor referral/commission model. In March 2026, SherWeb closed its first outside funding — a $125 million CAD minority equity investment from Investissement Québec — earmarked for international expansion, platform enhancements, and strategic acquisitions, concurrent with the announced entry into the UK market following the December 2024 MicroWarehouse acquisition in Ireland.

Name

SherWeb

Legal name

Sherweb Inc.

Website

https://sherweb.com

Company type

Private

Founded year

1998

Operating status

Operating

Headcount range

1,001–5,000 employees

Short description

SherWeb is a private cloud marketplace distributor founded in 1998, serving 7,500+ Managed Service Providers across Canada, the US, Ireland, and the UK through proprietary platforms (Cumulus, Self-Service Portal) and a curated portfolio of Microsoft, security, and backup solutions.

Ownership category

akta.pro rank

Product category

Cloud Marketplace Distribution Platform

NAICS

Computer Systems Design and Related Services (54151), Computer Facilities Management Services (541513)

SIC

Services-Computer Integrated Systems Design (7373)

akta.pro primary industry

Cloud Managed Services (M365/Azure/AWS/GCP) (BPAEABAE)

akta.pro secondary industries

Helpdesk & End-User Support Services (BPAEABAB), Data Security & Privacy Managed Services (DLP/Encryption) (BPAEADAL)

Keywords

• Cloud marketplace distribution
• Microsoft cloud solutions
• Managed service providers
• White-label IT services
• Cloud PSA integrations

Headquarters

HQ city

Newark

HQ country

United States

HQ region

North America

Offices5 records

Markets served

GTM type

B2B

Offering type

Software

Cost components

Personnel, Technology or R&D, Infrastructure, Marketing or Sales, Operations, Supply Chain

Revenue model

1. Cloud marketplace distribution (resale): Primary revenue stream: Sherweb purchases cloud licenses (Microsoft, security vendors, etc.) at wholesale and resells to MSP partners who bill end customers. Margins earned on the price spread.
2. Subscription / recurring license revenue: Recurring revenue from cloud subscriptions (Microsoft 365, Azure, security solutions) sold through partners on monthly/annual billing.
3. Professional Services: White-label outsourced IT helpdesk, Managed Detection and Response (MDR), NOC services, and certified specialist consulting for partners. Includes Microsoft program consultation services.
4. Managed Services: Recurring managed services revenue from MDR (Office Protect), NOC services, and white-label helpdesk offerings delivered 24/7/365.
5. Transaction fees / take rate on marketplace vendor sales: Revenue from third-party vendor products (security, backup, automation) listed on Sherweb marketplace, earning commissions/spread on partner transactions.
6. Partner referral / commission (Advisor model): One-time payment and recurring monthly commission to Advisor partners who refer clients to Sherweb for the life of the client's contract.
7. Performance Cloud (IaaS) revenue: Infrastructure-as-a-Service revenue from Performance Cloud servers (cloud computing, virtual machines) sold to channel partners.

Pricing tiers

Go-to-market motion4 records

Distribution channels7 records

Marketing channels8 records

Core offering

Sherweb operates a cloud marketplace and proprietary platform that enables Managed Service Providers (MSPs) to source, provision, bill and manage Microsoft 365, Azure, security, backup, productivity and infrastructure solutions from 45+ vendors. The platform combines the Cumulus partner control panel, a white-label Self-Service Portal, native PSA/RMM integrations and 24/7 expert support, complemented by managed services such as Office Protect (MDR for Microsoft 365), Performance Cloud (IaaS) and white-label helpdesk/NOC.

Differentiator

Problem solved

Functional benefit

Brands

• Office Protect: Security management solution for Microsoft 365 tenants, including 24/7 monitoring, threat detection and guided response via the Office Protect Alliance service.
• Cumulus
• Sherweb Self-Service Portal
• Performance Cloud
• Partner University
• MicroWarehouse
• C2 (C2 Enterprise / C2 MSP)
• PurelyHR

Products and services

• Sherweb Cloud Solutions Marketplace Curated cloud marketplace aggregating Microsoft 365, Azure, security, backup, productivity and infrastructure solutions from 45+ third-party vendors, enabling MSP partners to bundle solutions for their end-customers and grow recurring revenue.
• Cumulus Partner Platform Unified control panel for Sherweb MSP partners to manage billing, provisioning, account updates, license management, real-time reporting and multi-factor authentication; integrates with Microsoft Entra ID and is SOC2 Type II certified.
• Sherweb Self-Service Portal (white-label client storefront) White-label Progressive Web App storefront that lets MSPs' end-customers manage their own licenses, users and subscriptions 24/7/365; supports SSO via Microsoft Entra ID and Google Workspace, and integrates with ConnectWise for ticketing and PayPal for payments.
• Office Protect (MDR for Microsoft 365) Proprietary managed detection and response (MDR) service for Microsoft 365 tenants providing 24/7 monitoring, threat analysis and guided response via the Office Protect Alliance service.
• Performance Cloud (IaaS) Infrastructure-as-a-Service (IaaS) high-performance cloud server offering (cloud computing and virtual machines) sold to channel partners, originating from the July 2014 acquisition of ORCS Web Inc.
• Sherweb Professional Services (helpdesk, NOC, consulting) White-label outsourced IT helpdesk, Managed Detection and Response (MDR), NOC services, and certified specialist consulting for partners, including Microsoft program consultation services. Includes dedicated extension of partner teams for deployment, migration and optimization.
• Huntress cybersecurity platform (via Sherweb Marketplace) Huntress managed EDR, ITDR, SIEM and security awareness training distributed to MSP partners via the Sherweb Marketplace to protect endpoints, identities and data of end-customers.

Quantifiable outcome

• 400% year-over-year growth in Microsoft Copilot practice
• +4 more outcomes

Named customers3 records

Segments5 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature8 records

Partnerships

48 partnerships are on record, tiered flagship / strategic integration, core vendor in marketplace, core vendors in marketplace, flagship / strategic distribution partner, minor transactional partner, core vendor in marketplace / integration partner, core acquired entity (european market entry), strategic r&d / academic partnership, flagship / core technology partner, flagship / core psa integration, core psa integration, core accounting integration, core microsoft license management integration, flagship ai / productivity enablement, strategic gtm partner, core acquired entity, core acquired entity (historical), strategic services partner, strategic event partner, charity / community partner, historical distribution partner, core technology partner and core integration partner.

• HaloPSAflagship / strategic integrationTechnology or Integration · 28 May 2026Native integration that enables real-time synchronization of client, license, and service billing data between Sherweb's cloud marketplace and HaloPSA's PSA platform. Sherweb is the first cloud solution provider to integrate with HaloPSA natively, handling complex Microsoft billing scenarios including Azure consumption, annual commitments, and mid-cycle subscription changes. The integration pushes purchase and billing events directly into HaloPSA in real time, reducing manual reconciliation and billing errors.
• HelpGhostcore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 21 April 2026HelpGhost, an adaptive AI platform for MSP service delivery, added to Sherweb's marketplace. Turns the expertise inside every ticket into reusable knowledge and provides an on-demand AI assistant to technicians.
• Commvaultcore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 13 February 2026Commvault Cloud, a unified enterprise-grade data protection and cyber resilience platform, added to Sherweb's marketplace, helping MSPs simplify backup, recovery, and data security across on-premises, cloud, and SaaS environments.
• Palisadecore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 12 December 2025Palisade, an AI-powered platform for automated email authentication and DMARC management, added to Sherweb's marketplace to help MSPs secure client domains from spoofing.
• Afi, NordStellar, and Trend Vision Onecore vendors in marketplaceChannel Partner/ Reseller/ Distributor · 3 November 2025Three new security solutions (Afi, NordStellar, Trend Vision One) added to Sherweb's security and continuity portfolio, providing MSPs with comprehensive data backup, threat detection, and external monitoring.
• Huntressflagship / strategic distribution partnerChannel Partner/ Reseller/ Distributor · 7 October 2025Huntress's first-ever distribution partnership. All Huntress products (managed EDR, ITDR, SIEM, security awareness training) are available through the Sherweb Marketplace, empowering MSPs across North America, Ireland, and the UK to protect customers' endpoints, identities, and data. The partnership simplifies Huntress adoption and helps MSPs scale security offerings.
• Monjurcore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 18 September 2025Monjur, a contract-as-a-service platform designed for MSPs, has launched in Sherweb's cloud marketplace as its first distribution partner. Offers lawyer-verified templates, automated compliance updates (GDPR, HIPAA), and centralized contract management, helping MSPs streamline legal operations and reduce risk.
• DefensXcore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 20 August 2025DefensX secure browser tools block hackers from exploiting users' browsers as a path to infection, addressing a critical security gap for MSPs serving SMB clients.
• ClearlyIPminor transactional partnerStrategic or Co-development Partner · 18 August 2025Sherweb sold its Pulsar360 subsidiary to ClearlyIP, a recognized leader in VoIP and cloud communications. The transaction reflects a strategic alignment and a shared commitment to delivering exceptional service, allowing Sherweb to sharpen its focus on its cloud marketplace and MSP support.
• Kalibr8core vendor in marketplaceChannel Partner/ Reseller/ Distributor · 24 July 2025Kalibr8 added to Sherweb's cloud marketplace, offering advanced Azure cost optimization capabilities for MSPs to manage cloud spending, reduce waste, and streamline multi-tenant operations.
• NordPass and NordLayercore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 26 June 2025Sherweb added NordPass (password management) and NordLayer (network access) to its cybersecurity portfolio, helping MSPs deliver modern, scalable security for SMBs.
• ConnectSecurecore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 15 May 2025ConnectSecure's automated vulnerability management platform delivers end-to-end vulnerability management (asset discovery, vulnerability detection, risk-based prioritization) for MSPs through Sherweb's marketplace.
• HacWarecore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 9 May 2025Sherweb added HacWare to its marketplace, an AI-driven platform for phishing simulations and personalized cybersecurity awareness training, helping MSPs strengthen client defenses.
• IRONSCALEScore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 28 April 2025Sherweb launched IRONSCALES, an AI email security solution designed for MSPs that advances security in the channel beyond legacy platforms by combating phishing attacks in real time.
• usecurecore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 26 March 2025Sherweb launched usecure, an automated Human Risk Management (HRM) platform for MSPs, to its marketplace. usecure enables partners to automate and personalize ongoing cybersecurity training for individual employees, addressing the 95% of cybersecurity breaches caused in part by human error.
• Keepitcore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 13 March 2025Sherweb added Keepit to its data security portfolio, enabling MSPs to streamline backup and protection of data critical to their internal processes and workloads on Keepit's cloud-native platform. Strengthens Sherweb's defense against rising cyber threats.
• Rewstcore vendor in marketplace / integration partnerTechnology or Integration · 10 March 2025Sherweb added Rewst, an orchestration and automation platform purpose-built for MSPs, to its marketplace. Offering native multi-tenant support and integrations with widely used MSP tools, Rewst automates repetitive tasks and helps 7,500+ MSPs enhance efficiency.
• Check Point Software Technologiescore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 23 January 2025Sherweb launched Check Point Harmony Email & Collaboration (formerly Avanan) and Check Point Harmony SASE (formerly Perimeter 81) to secure the workspace. Demonstrates Sherweb's commitment to equipping MSPs with cutting-edge cybersecurity solutions.
• Proofpointcore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 23 January 2025Proofpoint service schedule referenced on Sherweb's legal page; available in the Sherweb marketplace for email security.
• Wasabi Technologiescore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 12 January 2025Wasabi's hot cloud storage added to Sherweb's product offerings, providing partners with a high-performance, simple, secure, and cost-efficient storage solution to address fragmented storage challenges.
• MicroWarehousecore acquired entity (european market entry)Strategic or Co-development Partner · 10 December 2024Sherweb acquired MicroWarehouse, a prominent player in the Irish cloud market, to expand its global cloud marketplace footprint and enter Europe. MicroWarehouse continues to operate as a local business unit in Ireland while leveraging Sherweb's resources and expertise.
• Keeper Securitycore vendor in marketplaceChannel Partner/ Reseller/ Distributor · 2 December 2024Keeper Security, a purpose-built password management solution for MSPs, was added to Sherweb's marketplace. Combines ease of use with advanced security features to protect digital credentials and streamline password management for MSPs and their SMB clients.
• University of Sherbrookestrategic r&d / academic partnershipStrategic or Co-development Partner · 29 October 2024Sherweb committed $1.5 million CAD to help fund a new Cybersecurity Expertise Centre at the University of Sherbrooke, aligning with Sherweb's increased focus on cybersecurity services for MSPs.
• Microsoftflagship / core technology partnerStrategic or Co-development PartnerMicrosoft is Sherweb's foundational technology partner. Sherweb is a Microsoft Cloud Solution Provider (CSP) with 20+ years of experience, 195+ certifications, all six Solutions Partner designations, and is one of the first Microsoft partners to earn the Support Services designation. Sherweb's marketplace centers on Microsoft 365, Azure, Microsoft Security, and Dynamics 365 offerings, and supports partners navigating Microsoft CSP-to-AI Cloud Partner transitions.
• SentinelOnecore vendor in marketplaceChannel Partner/ Reseller/ DistributorSentinelOne's AI-powered security platform (including Purple AI) is available through Sherweb's marketplace, giving MSPs access to endpoint, cloud, and network protection. Sherweb was the first cloud solution provider to offer SentinelOne's Purple AI to the MSP community.
• Veeamcore vendor in marketplaceChannel Partner/ Reseller/ DistributorSherweb is a Gold Veeam Cloud & Service Provider (VCSP) partner. Veeam-powered management console, license rental, and integrated storage are available in the marketplace, including Veeam Data Cloud for SaaS-based backup of Microsoft 365, Entra ID, and Salesforce workloads.
• Acroniscore vendor in marketplaceChannel Partner/ Reseller/ DistributorSherweb added Acronis Cyber Protect Cloud to its marketplace, providing MSPs with an integrated platform combining backup, disaster recovery, anti-malware, and endpoint protection. Sherweb was recognized as Acronis #CyberFit Partner of the Year - Canada in 2020.
• ConnectWiseflagship / core psa integrationTechnology or IntegrationNative ConnectWise integration synchronizes and automates billing, proration, and subscription info, with ticketing integrated into Sherweb's Self-Service Portal. Listed in the ConnectWise Marketplace.
• Autotaskcore psa integrationTechnology or IntegrationIntegration automates and syncs billing with accurate proration and subscription details to maximize efficiency for MSPs.
• Kaseya BMScore psa integrationTechnology or IntegrationIntegration streamlines financial processes and transactions by syncing Sherweb offers, prices, and services for increased efficiency.
• QuickBooks (Desktop & Online)core accounting integrationTechnology or IntegrationConnect and automate billing, invoicing, proration, Sherweb offers, and pricing through QuickBooks.
• CIPPcore microsoft license management integrationTechnology or IntegrationEnables partners to purchase licenses directly in CIPP with automated NCE migrations, real-time licensing visibility, user creation wizard, and offboarding workflows.
• Microsoft Copilotflagship ai / productivity enablementStrategic or Co-development PartnerSherweb helps partners deliver Microsoft Copilot to clients through a structured AI readiness consulting program. Reported 400% year-over-year growth in the Copilot practice as MSPs accelerate AI adoption.
• Trend Microcore vendor in marketplaceChannel Partner/ Reseller/ DistributorSherweb partnered with Trend Micro to offer Worry-Free Services to MSPs, an easy-to-manage security suite for advanced threat defense across endpoints and beyond. Also added Trend Vision One in 2025.
• Bitdefendercore vendor in marketplaceChannel Partner/ Reseller/ DistributorBitdefender Antivirus added to Sherweb's security portfolio to provide partners with advanced threat protection capabilities.
• Malwarebytes (ThreatDown)core vendor in marketplaceChannel Partner/ Reseller/ DistributorThreatDown powered by Malwarebytes is available in the Sherweb marketplace, providing endpoint security solutions for MSPs.
• RBC (Royal Bank of Canada)strategic gtm partnerGTM or Marketing PartnerSherweb and RBC collaborated to help Canadian businesses accelerate digital transformation as part of RBC's Go Digital program, helping SMBs manage transformation journeys.
• PurelyHRcore acquired entityStrategic or Co-development PartnerSherweb acquired PurelyHR, a Canadian leader specializing in HR management software solutions, expanding its service offering with HR management capabilities.
• C2 (C2 Enterprise)core acquired entityStrategic or Co-development PartnerSherweb acquired C2, a Canadian IT leader specializing in integrated ITSM software solutions. Acquisition consolidates Sherweb's position as a leading added-value solutions provider.
• Global Mentoring Solutions (GMS)core acquired entityStrategic or Co-development PartnerSherweb acquired Global Mentoring Solutions Inc., a North American support and IT management business specializing in white-labeled MSP support, such as helpdesk and NOC services.
• ORCS Web (OrcsWeb)core acquired entity (historical)Strategic or Co-development PartnerSherweb acquired OrcsWeb, a leading Windows-based managed hosting provider, accelerating its entry into the competitive Infrastructure-as-a-Service (IaaS) segment.
• CMIT Solutionsstrategic gtm partnerStrategic or Co-development PartnerSherweb forged a strategic partnership with CMIT Solutions, the leading managed services provider of enterprise-level IT services to the SMB market, to strengthen cloud service offerings.
• Bam Boom Cloudstrategic services partnerStrategic or Co-development PartnerSherweb and Bam Boom Cloud jointly offer Microsoft Dynamics 365 Business Central implementation services to help partners maximize their success in the cloud Business Applications market.
• Devolutionsstrategic event partnerGTM or Marketing PartnerSherweb partnered with Devolutions to present the 3rd edition of ITSec, an IT security summit held in Saint-Hyacinthe, Quebec, bringing together IT professionals and MSPs for presentations, workshops, and networking.
• Leucancharity / community partnerOthersSherweb has an ongoing charitable partnership with Leucan, a Quebec-based charity organization supporting children with cancer. Sherweb has raised CA$35,004 (2023), $33,600 CAD (2024), and 43,044.30 CAD (2022) through annual fundraisers.
• Arrow Electronicshistorical distribution partnerChannel Partner/ Reseller/ DistributorSherweb signed a North American distributorship agreement with Arrow Electronics, enabling Arrow to actively market Sherweb's industry-leading line of cloud services to all of its United States and Canada-based solution providers.
• VMware by Broadcomcore technology partnerStrategic or Co-development PartnerSherweb achieved Premier Partner status in the VMware Cloud Service Provider (VCSP) program within the Broadcom Advantage Partner Program, supporting MSPs with virtualized infrastructure solutions.
• Google Workspacecore integration partnerTechnology or IntegrationGoogle Workspace service schedule referenced on Sherweb's legal page; supports SSO for the Self-Service Portal.

Scale indicators9 records

Recent moves9 records

Expansion highlights7 records

Others

• ConnectWise: ConnectWise is the largest PSA platform for MSPs and a deep integration partner of Sherweb (with a marketplace listing and ticketing integration). While not a direct cloud distributor, it is comparable as a competing platform that MSPs use to run their business and that shapes how cloud services are bought and managed.
• Auvik: Auvik is a leading MSP-focused network monitoring and management vendor. While not a cloud distributor, it competes for share of MSP wallet and tooling budget alongside Sherweb's marketplace and is comparable as a category-defining vendor in the MSP technology stack.

Emerging players

• Rhinox (Rhino Distribution): Rhinox is a smaller cloud marketplace/distributor serving MSPs with Microsoft, security, and SaaS solutions. It competes with Sherweb in the same MSP channel but at a meaningfully smaller scale and with a narrower geographic footprint.
• Sherpa (Sherpa Software / independent CSP distributors): Independent Microsoft CSP Indirect Providers and smaller specialty distributors serve a similar MSP reseller audience with cloud license distribution. They are comparable to Sherweb in business model and target customer but typically operate with narrower product portfolios and limited international reach.

Broad incumbents

• Kaseya: Kaseya is a broad MSP platform vendor (RMM, PSA, security) that competes with Sherweb for MSP mindshare and wallet share, particularly through Kaseya BMS which integrates with Sherweb. It is comparable as an adjacent competitor targeting the same MSP buyer with overlapping (but not identical) capabilities.
• TD SYNNEX: TD SYNNEX is a large global IT distributor with a significant cloud solutions practice including Microsoft CSP. It competes with Sherweb for MSP and reseller cloud distribution volume but as one offering within a much broader hardware, software, and services portfolio.
• Ingram Micro Cloud: Ingram Micro Cloud is the cloud arm of one of the world's largest IT distributors, offering a broad cloud marketplace that overlaps directly with Sherweb's Microsoft and security offerings. It is comparable as a competing marketplace and CSP aggregator but operates as part of a much wider distribution portfolio.

Direct peers

• Pax8: Pax8 is the largest pure-play cloud marketplace for MSPs and Sherweb's closest direct competitor. Both companies aggregate Microsoft, security, and infrastructure solutions for the MSP channel with white-label portals, partner programs, and PSA/RMM integrations — Pax8 simply operates at larger scale and with deeper venture funding.
• ALSO Cloud Marketplace: ALSO operates a large pan-European cloud distribution marketplace serving resellers and MSPs with Microsoft, security, and SaaS solutions. It is the most direct European competitor to Sherweb as Sherweb expands into Ireland and the UK.
• Crayon: Crayon is a Norwegian-headquartered software and cloud economics distributor with a strong Microsoft CSP practice serving resellers and MSPs across EMEA. It is comparable to Sherweb in business model (cloud license distribution plus advisory services) and a likely competitor in the European expansion.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/SherWeb
• Facebookfacebook.com/sherweb
• LinkedInlinkedin.com/company/1022548

Revenue estimate

Valuation estimate

Number of profiles

Profiles14 records

Subsidiaries6 records

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A5 records

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about SherWeb