Last year I started using LilyPond and I really like it. I also became rookie hobbyist composer (check my SC profile's About box if you want to know a bit more about me). I write down my musical thoughts using Frescobaldi on Linux. Here you can have a taste of my works:
In memory of Change 123 - Motoko in danger.pdf
In memory of Change 123 - Fujiko x Zero.pdf
In memory of Change 123 - Birthday (draft - has engraving errors).pdf
In memory of Change 123 - MIDI output recorded in foobar2000 + foo_midi using SGM-V2.01 soundfont @SoundCloud
Imprints - Rain's tears.pdf
Imprints - Sun's rays.pdf
Imprints - River's current.pdf
Imprints - Wind's whisper.pdf
Imprints - Sea waves (draft - has engraving errors).pdf
Imprints - MIDI output recorded in foobar2000 + foo_midi using Yamaha Clavinova Grand (198-Clavinova.sf2) on top of SGM-V2.01 soundfont @SoundCloud
Recordings have not been done on Linux as I find BASSMIDI Driver more reliable so far than Linux synthesizers (check also my other thread).
I hope you'll like at least one of my pieces.