Ever wonder why you can't use the hydrogen you can harvest with Nils277's Kerbal Planetary Base Systems to power Nertea's Cryogenic Engines? Wound up with excess LH2 and yet somehow you can't power your TAC Life Support Sabatier reactions so now your kerbals are dying of thirst?
Hydrogen Compression is a simple way to work across these, and other related mods. Now, your 1.25m and 2.5m Convert-O-Trons can compress hydrogen into liquid hydrogen, evaporate liquid hydrogen into a gas again, or even choose to refine ore into gaseous hydrogen instead of liquid.
As of version 2, it now also handles oxygen (liquid/gas, ore processing), and flags.
If you're inclined, feel free to pick it up.
Hosted on Curse, Spacedock, and theoretically on CKAN.