We launched a WINE-based version of Picasa for Linux in 2006 as a Google Labs project. As we continue to enhance Picasa, it has become difficult to maintain parity on the Linux version. So today, we’re deprecating Picasa for Linux and will not be maintaining it moving forward. Users who have downloaded and installed older versions of Picasa for Linux can continue to use them, though we won’t be making any further updates.
The last Picasa for Linux version is 3.0, while Picasa for Windows has already reached version 3.9 and even though the Windows version is not officially supported on Linux, you can still use it and even get the Google+ integration working – see our Install Picasa 3.9 In Linux And Fix Google Sign In Issue [Wine] post for more info.