Google released a new version of the reference libwebp library that implements the latest features of Google's WebP image format.

All the major new features — Exif/XMP metadata, ICC profiles, and animation — were anticipated since the very beginning of the project. Both hardware accelerated viewer (vwebp) and encoder (cwebp) have been updated to support them. However they don't check validity of metadata and/or emebedded ICC profiles.

Additionally two more applications have been added/updated:

gif2webp, which is self-explanatory;

webpmux, a WebP muxer, now can create animations and takes WebP files for input and output.

Shortly before the release Mozilla removed “WON'T FIX” from the original request to add support for WebP in Firefox:

We decided to re-open this based on new data that shows that WebP has valid use cases and advantages. We will evaluate a refreshed patch and take it from there.

Right after that they moved the discussion to a new bug report, where contributors post new patches.

The existing plug-in for GIMP hasn't been updated yet.

You can download the libwebp library at Google Code.