• libsdl1.2
• libSDL_gfx
• libSDL_ttf
• libjack2
• (also libx11 for *nix targets)

• windows builds: refer to README-MINGW.md
• *nix builds:

 $ ./configure
 $ make
 # make install

if the build does not succeed, you could try reconfiguring autotools first:

 $ autoreconf -ifv
 $ ./configure
 $ make
 # make install

NOTE: make install is optional. loopidity can be run in-tree.

• start JACK first!
• if installed:

 $ loopidity

• or, run in-tree:

 $ ./src/loopidity

the wiki describes how loopidity works and how to use it.