Adding features takes quite some time and there are many requests for additions.
Because of this I use Git Hub issues to manage requests. If you've done the research yourself already, you can also submit a feature on Git Hub.
The caniuse browser scores are tallies of all features tracked on caniuse (excluding those marked as "unofficial").
The fully opaque part represents supported features, the semi-transparent part represents partial support.
Note that while caniuse tracks a wide variety of features, it only covers a subset of all web technologies so the scores are not 100% representative of any browser's capabilities.
"Can I use" provides up-to-date browser support tables for support of front-end web technologies on desktop and mobile web browsers.
The site was built and is maintained by Alexis Deveria, with occasional updates provided by the web development community.