A number of small governments were born with the colonization boom, mostly in the Sol System. These are generally not powerful or wealthy, and are often worker-led or founded by corporations or organizations. Most of these find assistance by the United Nations a common and vital occurrence, and some have even found themselves at odds - if not in conflict - with other nations.
A grassroots alliance of Rural Martians, spread out over most of the inhabited surface of Mars. The UMC is a democratic republic, but quite "town-esque" in the sense that its proceedings and rules are kept in a datapad in their main hall, which itself is a grounded colony ship hull where the representatives of the major colonies meet to discuss matters. Despite this, UMC citizens are fervent and quite happy to be part of the organization, partly due to the novelty of the alliance and due to the extreme similitude between its members: miners, welders, farmers and other blue-collar workers. The number of members in the UMC varies often, as colonies join and leave, attracted by the UMC's benefits or drawn away by more salacious offers.
The ASC is marginally, technically, a government. The only "solid ground" the ASC has is Homeland Dispatch 1, their base station and where most Alliance ships find themselves. This Alliance, for the most part, shares a similar history to Sealand: a micronation vastly unrecognized but still alive mostly due to memes and a solid sense of humor. Differently, the ASC and Homeland Dispatch 1 have actually grown massively, thanks to the Alliance's offer for collective funding and a sort of community system, through which captains and spacers can find help and aid. The Arabian League and a few independent governments recognize the Alliance.
The Syndicate is a somewhat formal government, made up of a number of questionably legal stations, colonies and settlements. The Syndicate itself is actually a vague denomination for a number of smaller groups that join together to make their voice heard, a faint attempt at politics by pirates, smugglers, anarchists and terrorists that usually just fails. The only thing that has stuck is the sense of belonging: the Syndicate is the home for renegades, the dishonorably discharged and those with no way or intention to lead life legally. The Syndicate is everywhere, and is the biggest threat to a stable Sol as of now.
Made up of Mondhafen and eleven other dome cities and settlements, Luna Europea is the newest member of the European Federation, having requested its independence once commerce and tourism had funded it and populated it enough to challenge the size of some European cities. Its independence was granted quite gladly, and Luna Europea now enjoys representation in the federal bodies. Luna is often considered among the snobbiest members of the Federation, frequently clashing with more affluent nations like Germany and France claiming its perceived importance and fame.
The Russian Republic of Europa, or Europan Russian Republic to make the acronym palatable, is a small colony of the United Russian Republics currently entirely submerged in the ocean of Europa, hung from the ice sheets. Often described as one of the worst places in the galaxy given the high rates of High-Depth Antisocial Personality Syndrome, the lack of light and the harsh working conditions. Europan Russians are usually considered horrendous masochists who suffer "in the name of the Republics" and slave away to supply the URR with the precious gases, data and minerals that occupy the European waters.