Is there a better way to report the bug than just use the built-in crash reporter? I still get super sporadic crashes, I think it has to do with having too many tabs loaded.
Yes, if you follow one of the links from about:crashes, you can see the crash report. If there's already a bug on file for it, click on over to bugzilla.mozilla.org and see if you may be able to help out there. If there isn't already a bug active for your specific crash signature, you can try filing one and explain what you think may have caused the crash. Specific steps to reproduce a crash are especially helpful!
Another interesting thing you can do: click through from about:crashes to your crash report. Then click the "more reports" link. You can see if your crash signature is rare or if you have one of the currently "popular" ones. If a lot of other people are crashing with that same signature, there is probably a bug and developers are probably discussing it. Again the most useful thing you can do is figuring out how to make that crash happen consistently and adding steps to reproduce it to its bug.
Running many WebGL demos. Whereas in Chrome only 1 tab will freeze.
Also, pretty much anything that's Javascript + WebGL runs like shit in Firefox. Emscripten demos are good though. But Emscripten runs better in Chrome than JS+WebGL in Firefox.
Compiling all those shaders is rough on any browser, but only Firefox gets its entire UI blocked. Even Internet Explorer manages to isolate the jank to one tab.
Chrome 1+, IE 9+ and Safari 7+ spawn child processes with less permissions ("sandbox") for almost every tab.
Sadly Firefox 39 (nightly) still has no real multi process support. There are only two processes, the main process holds all tabs, the single child process "plugin-container" holds all plugins (Flash, Acrobat, etc.). It's a bit disappointing to see such little progress since 2010. Hopefully Mozilla's Rust based Servo engine comes to the rescue soon and replaces gecko and its old XUL (XML based UI framework) with Servo and an HTML5 based UI (like Firefox OS).
I use Firefox as development browser because of Firebug and and the new developer tools. Working with dozens of tabs open for days is only possible with IE11 and Chrome.
"Sadly Firefox 39 (nightly) still has no real multi process support. There are only two processes, the main process holds all tabs, the single child process 'plugin-container' holds all plugins (Flash, Acrobat, etc.)."
That is incorrect. There is one plugin-container for each plugin module. All Flash instances share a single plugin-container, all Acrobat instances share a single plugin-container, and so forth.
As for the e10s content process, for the moment there is only one content process. The plan is to get e10s working well with the one content process, and then start scaling that up to multiple content processes. Nightly is a bleeding edge development channel, after all.
How do you get Firefox to crash? What does about:crashes say? Did you report the bug?