head to head · open source
Zen Browser vs opal
Zen Browser has 45,517 GitHub stars, 1,946 forks, 689 open issues and last shipped yesterday. opal has 4,930 stars, 338 forks, 152 open issues and last shipped 2 months ago. Zen Browser leads on adoption by 823% (45,517 vs 4,930 stars). Zen Browser is written in C++ under MPL-2.0; opal is written in Ruby under MIT. Zen Browser has attracted 4% as many forks as stars, opal 7%. Zen Browser was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
← all 20902 open source comparisons
Side by side
| Zen Browser | opal | |
|---|---|---|
| GitHub stars | ★ 46K | ★ 4.9K |
| License | MPL-2.0 | MIT |
| Written in | C++ | Ruby |
| Last push | 2026-11-02 | 2026-09-13 |
| Forks | ⑂ 1.9K | ⑂ 338 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Zen Browser if
- You weight community size — 46K stars and counting
- You want the MPL-2.0 license terms
- Your stack matches C++
- You value the larger contributor base for long-term maintenance
pick opal if
- You want the opal feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Ruby
- You evaluated both and opal fits your workflow better
About Zen Browser
Zen Browser Zen is a firefox based browser with the aim of pushing your productivity to a new level! Download • Website • Documentation • Release Notes Firefox Versions Release Is currently built using Firefox version 155.0.1 ! Twilight Is currently built using Firefox version RC 155.0.1 ! Contributing If you'd like to report a bug, please do so on our GitHub Issues page and for feature requests, you can use GitHub Discussions. Zen is an open source project, and we welcome contributions from the community! Please take a look at the contribution guidelines before getting started! Partners Thanks to all the…
read the full Zen Browser overview →
About opal
Opal Opal is a Ruby to JavaScript source to source compiler, shipping with an implementation of the Ruby corelib and stdlib. Write Ruby, run it anywhere JavaScript runs — the browser, Node.js, Deno, Bun, QuickJS. Why Opal A real Ruby implementation. Opal ships its own corelib and stdlib and is validated against [ruby/spec][ruby spec], the same suite CRuby uses. A JavaScript host imposes limits — those are catalogued in Unsupported Features. Source to source, no runtime interpreter. Ruby compiles to plain JavaScript ahead of time, so there is no VM to download and no interpreter loop at runtime. Two way…
More in Productivity & Utilities
Related comparisons
More Browsers & Extensions projects
Compare either of these against the rest of the Browsers & Extensions field.
Frequently asked questions
Is Zen Browser or opal more popular?
Zen Browser has 45,517 GitHub stars and opal has 4,930. Zen Browser has the larger community by that measure.
Are Zen Browser and opal free?
Both are open source. Zen Browser is licensed under MPL-2.0 and opal under MIT. Neither carries a licence fee.
What is the difference between Zen Browser and opal?
Zen Browser is written in C++ and opal in Ruby. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Zen Browser or opal?
Choose Zen Browser if you want the larger community (45,517 stars) or its MPL-2.0 licence terms. Choose opal if its feature set, stack or MIT licence fits better. Both are self-hostable.