I use thunderbird as my primary RSS feed reader. Lately thunderbird has been very slow to load and very sluggish. I want to try out liferea. Is there any way to export my subscriptions to liferea ( OPML or otherwise)?
In Thunderbird click Manage Subscriptions in the Blog & News Feed account main page, select Export, choose a folder and click Save.
In Liferea, click Subscriptions >> Import Feed List, select the opml file exported by Thunderbird, click Import.
Personally, I don't like Thunderbird or Liferea for feeds, because I like to read them inside the browser. I'm currently using Opera, but I have posted a few suggestions for standalone and other types of readers at http://askubuntu.com/questions/9757/
You could also optimize your Thunderbird. Compact your mail folders from "File >> Compact Folders". This should improve performance.
I don't use it and never tried to optimize it, like I do with Firefox. But since it is a Mozilla XUL application that uses sqlite, you could also try to optimize the databases with the following script. You will need sqlite3 command-line interface: