- [Regexr](http://regexr.com/) - RegExr is a HTML/JS based tool for creating, testing, and learning about Regular Expressions. ([Source Code](https://github.com/gskinner/regexr)) `MIT``Nodejs`
- [RStudio Server](https://www.rstudio.com/products/rstudio/#Server) - Web browser based IDE for R. ([Source Code](https://github.com/rstudio/rstudio)) `AGPL-3.0``Java/C++`
- [Slingcode](https://slingcode.net/) - Web app IDE and computing platform in a single static HTML file. ([Demo](https://slingcode.net/slingcode.html), [Source Code](https://github.com/chr15m/slingcode/)) `MIT``HTML`
- [sourcegraph](https://sourcegraph.com) - Sourcegraph is a fast, open-source, fully-featured code search and navigation engine written in Go. ([Source Code](https://github.com/sourcegraph/sourcegraph)) `Apache-2.0``Go`
- [Wakapi](https://github.com/n1try/wakapi) - Tracking tool for coding statistics, compatible with WakaTime. `GPL-3.0``Go`