"Fluajho" (with jh as in pleasure) means fluid in Esperanto. It is a simple sf2 soundfont host/player for Linux. Behind the scenes the Fluidsynth library is at work, hence the name.
This program is feature-complete with version 1.7.1 in 2022. Further releases will be limited to maintenance and fixing problems.
.sf2 is an old file format for making MIDI signals audible through virtual instruments, although it is still in moderate use today.
Why does Fluajho exist? There are already many soundfont players for Linux, most of them even based on Fluidsynth. Fluajho was written for a clearly defined use case: Load an .sf2 in the New Session Manager (Agordejo) and save the soundfont in the session directory. This makes it possible to archive the session, for example as a backup or to share it.
If you already have a DAW, host or plugin that reliably saves soundfont files together with the session you do not need Fluajho.
You can load one soundfont file per Fluajho instance. Each instance holds 16 of the soundfonts instruments that can be assigned to 16 MIDI channels. All access to MIDI parameters like Volume or Pan needs to be done via midi control changes.
Finally connect external sequencers, such as Laborejo or Patroneo, through JACK-Midi to play the instruments. There is only one JACK-Midi input but each of the 16 midi channels has it's own stereo JACK audio output. Additionally there is a stereo mix output pair.