Since Blockland's been on Steam for a while, we might as well add Workshop support for Blockland.
How it works is you can upload decals, prints, blocks, tools, weapons, events, things like that and they can be downloaded just like any normal Add-On is downloaded.
There can also be an 'exporter' wand or something like that added. It works similar to the duplicator wand Add-On, and you can select a building and add it to the workshop, maybe via the ESC menu. Then it can be loaded in the Load Bricks menu, maybe under a Workshop category.
It can also be a decent replacement for RTB. r.i.p.