Open Source Candies
The Free-for-Open-Source Services List
Formerly started at 
YCombinator
Pull Requests welcome!
[<img src="%favicon_url%" alt="%service_name%" height="16" /> %service_name%](%service_url%) - %description% - %rules%
In alphabetical order, please
Version Control
BitBucket - free for open source and private repositories
codeberg - free as in freedom for open source repositories - backed by a nonprofit association
GitHub - free for open source repositories, free for private repositories
GitLab - free for open source and private repositories
Heptapod FOSS - free of charge service for open source Mercurial repositories - upon hosting request
Project Hosting
NuGet - free .NET Project Hosting
Python Anywhere - hosting for Python projects - has limits
SourceForge - Git/Mercurial/SVN Project Hosting
DigitalOcean - free credits for eligible open source projects - request needed
Public Cloud
OpenShift - free for open source - request needed
Heroku - free tier for experimenting, sleeps after 30 minutes of inactivity
Vercel - free tier includes all-in-one Static and JAMstack deployment, Serverless Functions, and Global CDN (formerly ZEIT Now)
Documentation
GitBook - free for open source - request needed
Read the Docs - automating building, versioning, and hosting of your docs - free for open source
Atlassian Confluence - free for open source - request needed
Continuous Integration and Code Coverage
AppVeyor - Continuous Integration for .NET and many open source languages on Windows
Azure Pipelines - Azure Pipelines offers cloud-hosted pipelines for Linux, macOS, and Windows with unlimited minutes for open source projects.
Atlassian Bamboo - Continuous integration, deployment, and delivery on your own server - free for open source - request needed
Bitrise - Continuous Integration for mobile
CircleCI - Continuous Integration and Delivery - 3 extra containers
Codecov - Continuous Code Coverage
Codeship - Continuous Integration and Delivery for several languages, also supports Docker
Coveralls - Code Coverage History
Deploy - Continuous Deployment - email request needed
DeployBot - continuous deployment for GitHub, BitBucket or your own Git/SVN repository - free for one repository
Gitlab-CI - on-premises CI for GitLab - free and open source
Sauce Labs - CI for GitHub, Google Code, SourceForge with Selenium - free for open source
Scrutinizer - CI for GitHub and BitBucket - free for open source
Semaphore - CI for GitHub and BitBucket - free for open source
Team City - free for open source - strict rules - request needed
Travis CI - CI for GitHub - free for open source
Knapsackpro - Speed up your tests run 1 hour test suite in 2 minutes with optimal parallelisation on your CI - request needed
Browser Testing
Browser Stack - Live, Web-Based Browser Testing - request needed
LambdaTest - Live ,Web and Mobile App Browser Testing - request needed-Free For Open Source
TestingBot - Browser Testing - request needed
Monitoring
Bugsnag - Multilanguage Crossplatform Error Monitoring - free for open source - email request needed
Datadog - Real-time performance monitoring for open source projects - free for open source - request needed
Healthchecks.io - Cron monitoring - free for open source - email request needed
Hund - Hosted Status Pages - free for open source - email request needed
Sentry - 100% Open Source Crash Reporting - forever free for open source - request needed
Code Review
Codacy - Automated Code Review for Scala, JavaScript, PHP, Python and CSS - free for open source
CodeClimate - Code Review for Ruby, JavaScript, PHP - free for open source
LGTM - Continuous security analysis and automated code review - free for open source
QuantifiedCode - Automated Code Review for Python - free for open source
Snyk - Continuously find & fix vulnerabilities in your dependencies, supports multiple languages - free for open source and low volume private testing
SonarCloud - Code coverage, code smell, and bug/vulnerability detection and tracking
Localization
Crowdin - free for open source - request needed
Launchpad - Localization Platform for open source projects
Localeum - free for startups and solo developers
Localizely - free for open source - request needed
Lokalise - Localization and Translation Software Tool - request needed
POEditor - free for open source - request needed
Transifex - Localization Platform for Web
Translation.io - Localization for Rails apps - email request needed
Profiling
Blackfire - PHP Profiler by creators of Symfony
YourKit - Java Profiler
E-mail Sending
Helpmonks - Team email management. Simplified. - free for open source projects and non-profit organizations
MailChimp - free for 12,000 emails to 2,000 subscribers
EmailOctopus - free for 10,000 emails to 2,500 subscribers a month
SendGrid - free 100 emails / day
SendinBlue - free 300 emails / day
IDE
AppCode - Objective C IDE - free for open source, Outercurve developers - strict rules - request needed
IntelliJ Idea - Java IDE - free for non-Apache developers, Apache developers, Outercurve developers - strict rules - request needed
PhpStorm - PHP IDE - free for open source, Outercurve developers - strict rules - request needed
PyCharm - Python IDE - free for open source, Outercurve developers - strict rules - request needed
RubyMine - Ruby IDE - free for open source, Outercurve developers - strict rules - request needed
Visual Studio Community - free, fully-featured IDE for students, open-source and individual developers
VS Codium -
binary releases of Visual Studio Code without MS branding/telemetry/licensing
WebStorm - JavaScript, CSS, HTML IDE - free for open source, Outercurve developers - strict rules - request needed
Project Management
Acunote - Agile project management tool and scrum software - request needed
Atlassian Jira - Project management and issue tracking - free for open source - request needed
Taiga.io - Agile project management platform - free for public projects
Teamwork - free for 2 Projects, 10MB Storage
Trello - simple bugtracker - free for all
YouTrack - free for open source - strict rules - request needed
Zenhub - Team collaboration in GitHub - free for public and open source projects
Discourse.org - Civilized discussion forum for your team/customers/fans/patrons - request needed
Convas.io - Feedback page for your projects where your users can share, discuss and upvote feedback - request needed
Chat
Chatwoot - Customer engagement suite, an open-source alternative to Intercom, Zendesk, Salesforce Service Cloud etc - email request needed
Zulip - Group chat webapp and mobile app - Free hosted instance for open source projects & communities
SSL Certificates
Cloudflare - free Shared SSL cert for everyone, unmetered DDoS mitigation and Web Application Firewall
GoDaddy - free for one year for open source projects
Let’s Encrypt - free, automated, and open certificate authority
Digital Asset Management
Razuna - World's most popular open source Digital Asset Management. 30 days free trial
Design & Icons
Canva - free for all plan
Mixkit - free video footage & animation - attribution not required
Openclipart - Free clipart for all
Unsplash - Photos for free for all purpose - no link back required (although appreciated)
Misc. Application Utilities
Algolia - Hosted Search engine as a service - free for community and open source use, email request needed
Apiary - Design, prototype, document and test APIs - email request needed
Auth0 - Single Sign On & Token Based Authentication - request needed
Cloudflare - Pro Plan upgrade for open source projects, includes CDN, SSL cert, Web Application Firewalls, image and mobile optimizations, and more.
Kong - Developer Portals - email request needed
Mailtrap - Fake SMTP servers - email request needed
SDKMAN! - Software Development Kit Manager for JVM developers
Fonts
Fontpair - FontPair is a tool that helps you pair free, open source Google Fonts together - Free for all
Domain Names
js.org - Free .js.org domain names for JavaScript projects, perfect for use with GitHub pages
