God dammit Space Guy beat me to it while I was typing this novel of a post, feel free to read mine anyway if you wish to waste some time on my unnecessary knowledge of BL. And Space Guy: BLM added persistence saving I believe.
Back when Blockland was free, v0.0002 was known as "Vanilla Blockland" and had the very bare minimum. The very first mod was Skizot's Mod, which included a slew of new and useful features such as altering jet speed and new admin features, among many others. BLM (Blockland Mods) was next in line, it included a bunch of different mods (Including Skizot's Mods, somewhat to his disapproval) from lots of different devs. Next was AiO (All-in-One) which had a TON of different maps, mods, weapons and items from a ton of different developers. TBM (The Better Mod) came next, it was a serious mod that included a lot of powerful features like changing colorsets in game, situation dependent death animations, in depth brick editing, Gobble's brick copier which allowed you to make a bubble around your build and save it to a GUI and load it anywhere. TBM was somewhat of a hardcore player's mod for those who were very serious about building. RTB came out and demolished the competition with a money system, advanced admin abilities, new maps, the Editor Wand (Which allowed you to shape shift a brick any way you wanted and rotate it freely on its axis) among a ton of other super useful things. There was a huge war I don't feel like going into which led to the banning of all the TBM devs from the forums and bans at the mention of the mod. RTB reigned supreme over AiO and BLM (AiO eventually becoming AiO-R (R for Reloaded, of which I was a dev for) and BLM halting production at 1.6a) until Retail.
TL;DR: RTB was a mod for free Blockland that added a ton of useful stuff.
Oldcigarettes feel free to correct me, this is all just off the top of my head.
