It supports ALSA and OSS, but no mentin of JACK or
LADPSA;
There's a compilation guide:
http://sourceforge.net/forum/forum.php?thread_id=1177828&forum_id=409329
Quote:
"- Latest CVS snapshot of PortAudio v19
* You should be able to download it from:
http://portaudio.com/archives/pa_snapshot_v19.tar.gz
* We recommend to compile with ALSA support (--with-alsa) and
without JACK since jack support hasn't been really tested."
Best regards
ce