Part 1 is
here.
I'll say this for Intersolar - they don't skimp on off-world bases. There are currently 6 "colonies" on the Moon; each belonging to mining/low-G development corporations and consortiums.
Lunar One is owned by Star Petrochemical out at Fra Mauro. They mainly do work in low-G development and refinement techniques in the plastics industry. Good for them - it's a messy business; but there's no atmosphere to pollute on the Moon; waste is simply reclaimed or shot into the Sun.
AgriFutures Inc. has New Iowa at Mare Nectaris - it's a massive underground complex developing underground farming techniques. They produce amazing yields under low-G hydroponic conditions - they'll almost certainly be the major food supplier once colonization really takes hold up here.
Heinlein Base is of course owned by 3M; down at Mare Tranquilitatis. Underground mineral/chemical processing; but they've also got a pretty good tourism industry going at Armstrong Park. They couldn't take over Tranquility Base itself; it's a historical site, but they run regular tours out there. I did the tour a few years back - seeing the Eagle's descent stage still sitting there, untouched, sends a shiver up the spine. It's amazing what they did way back then with the technology of the day.
IAC owns the King Charles Memorial telescope complex; a colossal VLA array of radio telescopes on farside. Not much out there; but they seem to like it.
Sun City was built by Energy Holdings Inc. It's a solar farm ten thousand hectares across. Solar power is collected and beamed to the Sunflower satellite reciever in low Earth orbit; and from there to the planet. Powers most of central and eastern Canada; from Manitoba to Labrador.
Finally, Brighton Beach is owned and operated by Intersolar; up on the south 'coast' of Sinus Roris. It's primary purpose is low-G refinenment, processing and manufacture; its second goal is expansion.
No question; Brighton Beach is
big; it houses twenty thousand in underfround comfort. The only things aboveground are the Intersolar offices; insanely expensive condos, the raw resource monorail and of course the landing field - 6 pads; only Heinlein has more with 7.
It's a comfortable place to spend time as well;