Airwindows just released their entire back catalogue free and open source on Linux!!
http://www.airwindows.com/airwindows-linux/
There is a little video about most plugins telling you what they do:
https://www.youtube.com/user/airwindows/videos
With this and the u-he, I think the days of needing Windows for music production just ended! The quality and scope of the Airwindows back catalogue covers everything from console emulation to special mathematically perfect gain
Not long ago these were all commercial price plugins, so if you use them then support the guy on
https://www.patreon.com/airwindows
PS I have no connection with him, i am just sharing the good news.