What Distributed Proofreaders Foundation does

Distributed Proofreaders Foundation, Inc. is a 501(c)(3) nonprofit public charity operating the Distributed Proofreaders (DP) web platform, a volunteer-driven system that converts U.S. public domain books into high-quality e-books for the Project Gutenberg archive. The platform, accessible at pgdp.net, divides each book into individual pages and routes them through a structured multi-round workflow — three proofreading rounds (P1-P3), two formatting rounds (F1-F2), smooth reading, and final post-processing — enabling many volunteers to work on the same book concurrently. The completed titles, numbering 51,062 as of mid-2026, are submitted exclusively to Project Gutenberg for free global distribution.

The technology stack is a PHP-based web application with a custom proofreading interface, supplemented by MediaWiki for documentation, phpBB for community forums, and a suite of post-processing utilities including Guiguts, bookloupe, ppgen, and the Post-Processing Workbench. A proprietary asset, the DP Sans Mono font, is optimized to help volunteers visually distinguish between commonly confused characters (e.g., O vs. 0, l vs. 1) and has been extended with enhanced Unicode support to accommodate non-Latin scripts. The codebase is hosted on GitHub under the GPL v2 license and developed by a global volunteer contributor community.

The Foundation is funded entirely by donations and operates without a sales team, paid marketing, or pricing model; all services are free to volunteers and end readers. Governance rests with a volunteer Board of Trustees, with Linda Hamilton serving as General Manager since 2014. The organization's value proposition is mission-driven (preservation of literary history) rather than commercial, and its competitive position is anchored in a 25-year-old community of 189,029 registered members, established tooling, and its structural role as Project Gutenberg's primary content source.

Name

Distributed Proofreaders Foundation

Legal name

Distributed Proofreaders Foundation, Inc.

Website

https://pgdp.net

Company type

Private

Founded year

2000

Operating status

Operating

Headcount range

51–100 employees

Short description

Distributed Proofreaders Foundation operates a volunteer-run web platform that converts U.S. public domain books into e-books for Project Gutenberg through a structured multi-round proofreading workflow, serving a global community of 189,000+ registered volunteer contributors and readers.

Ownership category

akta.pro rank

Product category

Volunteer E-book Digitization Services

NAICS

Book Publishers (513130), Grantmaking Foundations (813211)

SIC

Books: Publishing Or Publishing & Printing (2731)

akta.pro primary industry

OER Authoring, Remixing & Publishing Tools/Platforms (EDAGAJAM)

akta.pro secondary industries

Digital Reading Content & eBooks (Leveled Readers, Libraries) (EDAFACAH), Open Educational Resources (OER) & Open Access Academic Publishing (MPAJABAG)

Keywords

• Crowdsourced proofreading
• Public domain e-books
• Volunteer digitization
• E-book conversion
• Literary preservation

Headquarters

HQ city

Marlton

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2C

Offering type

Services

Cost components

Operations, Technology or R&D, Infrastructure, Others

Revenue model

1. Donations: The organization is a 501(c)3 tax-exempt public charity (EIN 20-4682326) that relies entirely on monetary donations from supporters to fund operations and maintain the Distributed Proofreaders website.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels4 records

Core offering

Distributed Proofreaders Foundation operates a free, web-based crowdsourced proofreading platform that divides public domain book digitization into individual pages, allowing many volunteers to simultaneously proofread scanned page images against OCR text through multiple rounds. Completed e-books are submitted to Project Gutenberg for global free distribution. The service is funded entirely by donations and supported by an all-volunteer community of proofreaders, formatters, post-processors, and project managers.

Product overview

Distributed Proofreaders is a single unified web platform for digitizing public domain books through volunteer collaboration. The core platform (https://www.pgdp.net/c) enables crowdsourced proofreading via three proofreading rounds and two formatting rounds, followed by post-processing where volunteers assemble completed pages into e-books for Project Gutenberg. The platform includes Smooth Reading for quality review, the Post-Processing Workbench, Guiguts, bookloupe, and ppgen as supporting tools. The DP Sans Mono font is used for proofreading accuracy. Community collaboration is facilitated through the DP Wiki (MediaWiki-based) and DP Forums (phpBB-based).

Differentiator

Problem solved

Functional benefit

Products and services

• Distributed Proofreaders Web Platform A web-based volunteer proofreading platform at pgdp.net that converts public domain books into e-books for Project Gutenberg through multi-round proofreading and formatting workflows.
• Post-Processing Workbench

Quantifiable outcome

• 51,062 books preserved in Project Gutenberg archive
• +2 more outcomes

Segments2 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature1 record

Partnerships

Two partnerships are on record, tiered core and minor.

• Project GutenbergcoreStrategic or Co-development Partner · 1 January 2002Distributed Proofreaders serves as the main source of e-books for Project Gutenberg. The organization converts public domain books into e-books and submits them to the PG archive. DP became an official Project Gutenberg site in 2002.
• Registered Agents, Inc.minorOthersCorporate registered agent for service of process and official mail for the Distributed Proofreaders Foundation. Located at 525 Route 73 North, STE 104, Marlton, NJ 08053.

Scale indicators7 records

Recent moves7 records

Expansion highlights4 records

Broad incumbents

• Internet Archive: Internet Archive is a large nonprofit that operates Open Library and massive book/digitization programs. It overlaps with DP on public-domain preservation and crowdsourced metadata, but on a much broader scale and with paid staff.
• Google Books: Google Books is a large-scale commercial digitization program that has scanned millions of volumes. It overlaps with DP on book digitization but operates as a commercial incumbent with paid infrastructure and far broader scope.
• HathiTrust: HathiTrust is a large-scale collaborative digital preservation repository founded by academic and research libraries. It digitizes and preserves public-domain and in-copyright works, overlapping with DP on digital preservation of the literary record.

Direct peers

• Open Library: Open Library is an Internet Archive project that catalogs and curates book records with volunteer contributions. It shares DP's crowdsourced approach to making books accessible, though it focuses on cataloging rather than full text proofreading.
• Project Gutenberg: Project Gutenberg is the world's largest free public-domain e-book archive and DP's primary distribution partner. The two organizations share the same mission of preserving literary works in digital form and have been integrated since 2002.
• Librivox: Librivox is a volunteer-driven platform that produces free public-domain audiobooks. It mirrors DP's mission-driven, donation-funded, crowdsourced approach and complements DP by serving the audio modality of the same public-domain corpus.
• Wikimedia Foundation (Wikisource): Wikisource is a Wikimedia sister project that crowdsources the transcription and proofreading of public-domain texts. It uses a nearly identical volunteer-driven model and serves overlapping audiences seeking free, accurate literary content.

Emerging players

• Zooniverse: Zooniverse is the largest citizen-science platform, hosting volunteer-driven research projects including historical text transcription. It shares DP's volunteer crowdsourcing infrastructure and engagement model, though applied across many domains.
• Smithsonian Digital Volunteers (Transcription Center): The Smithsonian Transcription Center crowdsources volunteer transcription of historical manuscripts and archival documents. It mirrors DP's multi-round volunteer QA model but operates in a museum/archival context rather than books.

Regional players

• Distributed Proofreaders Canada: Distributed Proofreaders Canada is a direct fork of DP focused on Canadian public-domain works and feeds Project Gutenberg Canada. It uses nearly identical workflows and tooling, making it a close regional peer.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• GitHubgithub.com/DistributedProofreaders/dproofreaders
• LinkedInlinkedin.com/company/distributed-proofreaders-foundation

Revenue estimate

Valuation estimate

Number of profiles

Profiles4 records

Funding overview

Funding rounds

Investors

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

M&A

Investments

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

Frequently asked questions about Distributed Proofreaders Foundation