The Horde Project
The Horde Project is an open-source community initiative that builds a PHP-based groupware framework and webmail suite, serving self-hosting enterprises, ISPs, and developers who need standards-based email, calendar, contacts, and collaboration tools, funded primarily through corporate sponsorships and professional services.
- Company typePrivate
- Founded2001
- HeadquartersAtlanta, United States
- Headcount1–10
- GTM typeB2B
- OfferingSoftware
What The Horde Project does
The Horde Project is an open-source community project that develops a PHP-based groupware platform consisting of a reusable application framework and a suite of browser-based collaboration applications. Headquartered in Atlanta and founded circa 2001, the project is maintained by a small core team (1–10 personnel) including co-founders Jan Schneider and Michael J. Rubinsky, with developer Ralf Lang contributed via employer B1 Systems. The platform serves self-hosting enterprises, ISPs, and developers who need standards-based email, calendar, contacts, tasks, notes, file management, and wiki functionality without vendor lock-in; its claimed reach extends to millions of end users deployed across hosting providers and on-premise installations.
The product stack is anchored by the Horde Framework, a modular PHP framework, and Horde Groupware Webmail Edition, the integrated suite. Around twenty add-on applications extend the suite, including IMP (mail), Kronolith (calendar), Turba (contacts), Nag (tasks), Mnemo (notes), Gollem (file manager), Ansel (photo gallery), Wicked (wiki), Ingo (mail filters), Whups (ticketing), and Chora (repository browser). The platform supports CalDAV/CardDAV for calendar and contact sync, ActiveSync for mobile device integration, SyncML for legacy mobile sync, and LDAP for identity. Horde 6 is currently in beta (announced 2026), introducing modern PHP support, PHP-FIG standards adoption, hybrid JWT authentication, and a new Two-Factor Authentication API with a One-Time Password module.
Horde operates as a non-commercial open-source initiative: the core product is distributed free of charge under an open-source license, and there is no venture funding or public ownership. Recurring cash inflow comes from a tiered corporate sponsorship program (Bronze $100/month through Platinum $1,000/month) and from quote-based professional services for enterprise installations and custom development. Infrastructure is supported through partnerships with Hub.org (mailing lists, GitHub, Packagist hosting) and B1 Systems (server hosting plus developer time). Sponsors and testimonial customers include Hub.org, B1 Systems, intra2net, PSW GROUP, Synthesis AG (SyncML licensing), and AMMMa AG (affiliated with Jan Schneider); Ubiquity Hosting Solutions and The WebWonker are cited as independent endorsements.
The Horde Project firmographics
Firmographics- Name
- The Horde Project
- Legal name
- The Horde Project
- Website
- https://horde.org
- Company type
- Private
- Founded year
- 2001
- Operating status
- Operating
- Headcount range
- 1–10 employees
- Short description
- The Horde Project is an open-source community initiative that builds a PHP-based groupware framework and webmail suite, serving self-hosting enterprises, ISPs, and developers who need standards-based email, calendar, contacts, and collaboration tools, funded primarily through corporate sponsorships and professional services.
- Ownership category
- akta.pro rank
The Horde Project industry classification
Industry- Product category
- Open Source Groupware and Collaboration Software
- NAICS
- Software Publishers (5132), Computer Systems Design and Related Services (54151)
- SIC
- Services-Prepackaged Software (7372), Services-Computer Programming Services (7371)
- akta.pro primary industry
- Email, Calendar & Scheduling (BPAMAMAC)
- akta.pro secondary industry
- Project & Task Management (BPAMAMAF)
Keywords
Where The Horde Project is headquartered
LocationHeadquarters
- HQ city
- Atlanta
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
The Horde Project business model
Business model- GTM type
- B2B
- Offering type
- Software
- Cost components
- Personnel, Technology or R&D, Infrastructure, Operations
Revenue model
- Open Source Software Distribution: Free open source software distributed under open source license. Core product is freely available for download and self-hosting.
- Professional Services: Team of trusted professionals helps build large installations or custom applications. Consulting and implementation services for enterprise deployments.
- Sponsorship and Donations: Monthly sponsorships from Bronze ($100/month) to Platinum ($1,000/month) tiers. Funds support general Horde development and new features.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Freemium | Monthly | Free open source version |
| Subscription | Monthly | Bronze Sponsor |
| Subscription | Monthly | Silver Sponsor |
| Subscription | Monthly | Gold Sponsor |
| Subscription | Monthly | Platinum Sponsor |
Go-to-market motion1 record
Distribution channels4 records
Marketing channels8 records
The Horde Project product offering
Product offeringCore offering
The Horde Project develops and distributes a free, open-source, browser-based communication and groupware suite for managing email, calendars, contacts, tasks, notes, files, and wikis, built on a PHP-based modular framework. It also offers professional services for large enterprise installations and custom application development, and accepts tiered monthly sponsorships to fund ongoing development.
Product overview
The Horde Project is an open-source groupware platform based on PHP and the Horde Framework. The core product is Horde Groupware Webmail Edition, a free enterprise-ready browser-based communication suite. The platform follows a modular architecture where the Horde Framework provides the foundation for multiple add-on applications including IMP (mail), Kronolith (calendar), Turba (contacts), Nag (tasks), Mnemo (notes), Gollem (file manager), Ansel (photos), Wicked (wiki), Ingo (filters), Whups (tickets), Chora (repository), Sesha (inventory), Passwd (passwords), and more. Horde 6 is the upcoming major version in beta, promising support for latest PHP releases and improved CalDAV/CardDAV synchronization.
Differentiator
Problem solved
Functional benefit
Products and services
- Horde Groupware Webmail Edition Free, enterprise-ready, browser-based communication suite for sending, reading and organizing email, managing calendars, contacts, tasks and notes with users both inside and beyond their own network, with different interfaces for different devices and synchronization out of the box.
- Horde Framework Robust, standards-based PHP application framework that provides the foundation for all Horde applications and enables developers to build custom web applications capable of using existing platforms and backends.
- Professional Services Consulting and implementation services for large enterprise deployments of the Horde platform and custom application development on the Horde Framework, quoted per engagement.
Companies that use The Horde Project
Customer profileNamed customers2 records
Segments2 records
Ideal customer profiles2 records
The Horde Project technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Integration6 records
Feature6 records
The Horde Project partnerships and signals
Strategic signalPartnerships
Eight partnerships are on record, tiered core and minor.
- Hub.org Networking ServicescoreHub.org provides hosting services for Horde.org servers including mailing lists, GitHub, and Packagist. This is infrastructure support for the open source project.
- B1 SystemscoreB1 Systems provides hosting for Horde.org servers and employs developer Ralf Lang who works on Horde development. They also provide sponsorship support.
- Synthesis AGminorSyncML client licenses have been generously donated by Synthesis AG for use in Horde synchronization features.
- intra2netminorSilver sponsor donating funds to support general Horde development. Listed on the thanks page.
- PSW GROUPminorBronze sponsor donating funds to support general Horde development.
- topratedbingosites.co.ukminorBronze sponsor donating funds to support general Horde development.
- bingo gamesminorBronze sponsor donating funds to support general Horde development.
- AMMMa AGminorAward winning e-learning and knowledge management solutions company co-founded by Jan Schneider, core developer and founding member of Horde.
Scale indicators1 record
Recent moves6 records
Expansion highlights4 records
The Horde Project competitors and assessment
Company assessmentEmerging players
- iRedMail: Open source mail server solution bundling Postfix/Dovecot with a webmail frontend (often Roundcube) and optional groupware components. Comparable as an alternative open source email/collaboration stack that overlaps with Horde's webmail use case.
Direct peers
- Open-Xchange: Provider of OX App Suite, an open source email, calendar, contacts, and document platform targeted at ISPs, telcos, and enterprises. Direct competitor in the standards-based, self-hostable groupware category.
- Nextcloud: Open source, self-hosted collaboration suite (calendar, contacts, mail, files, talk) built on PHP. Direct competitor in the on-premises groupware category Horde serves, with overlapping standards-based sync and a much larger contributor base.
- Zimbra: Open source email and collaboration platform offering webmail, calendar, contacts, and tasks for service providers and enterprises. Competes head-on with Horde Groupware Webmail Edition for hosting-provider and on-prem deployments.
- BlueMind: Open source messaging and collaboration platform (mail, calendar, contacts, mobile sync) targeted at European enterprises and public sector. Competes in the same self-hosted, standards-based groupware category as Horde.
- Kolab Systems: Open source Kolab Groupware Server offering shared calendars, contacts, tasks, and notes, and a documented integration partner for Horde. Competes in the same privacy-focused, self-hosted segment.
- eGroupware: Open source groupware suite (calendar, email, CRM, projects) primarily used in European SMBs and public sector. Direct competitor in the open source, self-hosted collaboration category.
- Citadel: Open source groupware platform combining email, calendaring, address books, and bulletin boards in a single self-hostable server. Comparable as a community-driven, all-in-one alternative to Horde.
- SOGo: Open source groupware server with Webmail, CalDAV, CardDAV, and ActiveSync support. Targets the same self-hosted enterprise and ISP use cases as Horde and uses similar standards-based sync protocols.
- Roundcube: Open source PHP-based webmail client with calendar/contacts plugins. Closely comparable as a free, browser-based email/collaboration tool often deployed alongside or instead of Horde's IMP module.
Market position
Strengths4 records
Weaknesses4 records
Competitive moat4 records
Key risks5 records
Key highlights5 records
Customer concentration
The Horde Project social profiles
Digital presenceThe Horde Project financial estimates
Financial estimateRevenue estimate
Valuation estimate
The Horde Project leadership team
Management profileNumber of profiles
Profiles3 records
The Horde Project funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
The Horde Project M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about The Horde Project
What does The Horde Project do?
The Horde Project develops and distributes a free, open-source, browser-based communication and groupware suite for managing email, calendars, contacts, tasks, notes, files, and wikis, built on a PHP-based modular framework. It also offers professional services for large enterprise installations and custom application development, and accepts tiered monthly sponsorships to fund ongoing development.
Is The Horde Project a public or private company?
The Horde Project is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was The Horde Project founded?
The Horde Project was founded in 2001. It employs 1 to 10 people.
Where is The Horde Project based?
The Horde Project is headquartered in Atlanta, United States, in the North America region.
How does The Horde Project make money?
Three revenue lines are on record. Open Source Software Distribution is the primary driver. The others are professional Services and sponsorship and Donations.
Who are The Horde Project's main competitors?
iRedMail is listed as an emerging player. Direct peers are Open-Xchange, Nextcloud, Zimbra, BlueMind, Kolab Systems, eGroupware, Citadel, SOGo and Roundcube.
Does The Horde Project have an API?
No public API is recorded for The Horde Project.
What industry is The Horde Project in?
The Horde Project's product category is Open Source Groupware and Collaboration Software. Its primary akta.pro industry code is BPAMAMAC, Email, Calendar & Scheduling, with a secondary code of BPAMAMAF, Project & Task Management. Its NAICS code is 5132 and its SIC code is 7372.