> It's not really the API which breaks, it's the versioning.
It is definitely the API which breaks in many cases. These 6-week updates change APIs, both Web APIs (used by both websites and addons) and internal APIs.
For example, websites - not addons - can and do break with Firefox and Chrome 6-week updates, because even Web APIs are changed in these rapid updates.
It is true that versioning is a problem as well, however.
Firefox has been forced to follow Chrome on this AFAIK because otherwise some website features (popular ones.. specially GDocs) wouldn't work optimally. Even right now, loading Google sites is faster (specially GMail) on Chrome because only Chrome has SPDY support (coming in a Firefox near you in some weeks thanks to the fast release mechanism!)
The Web APIs aren't stable at many levels, and HTML5 ain't standard. It's a bunch of drafts and some are even conflicting (hello audio APIs).
It seems to me that Google is the main company right now pushing in new drafts and protocols - using it to make other browsers incompatible. Generally the drafts are technically fine and good, the issue is the way they're used to kill diversity and obtain complete web (or "internet") control.
You can start to see a lot of "you need Chrome to see this website. Chrome, the fastest browser on earth by Google! <click to download>.
Specially true if you use Opera or IE which do not update as often as Firefox and Chrome.
It is definitely the API which breaks in many cases. These 6-week updates change APIs, both Web APIs (used by both websites and addons) and internal APIs.
For example, websites - not addons - can and do break with Firefox and Chrome 6-week updates, because even Web APIs are changed in these rapid updates.
It is true that versioning is a problem as well, however.