DynaBlocks is the former name of Roblox, used between 1997 and 2004. Jim Stevens registered this site on December 12, 2003. In 2003, DynaBlocks' URL was GoBlocks.com, but this was later changed to DynaBlocks.com. It was then later renamed to Roblox in late 2004, due to DynaBlocks being "too hard" to remember. dynablocks.com, dynablox.com, and dynablock.com all redirect to roblox.com, and "Waiting for www.roblox.com" appears at the bottom of the screen.
The earliest form of the website that can be accessed is here. It can sometimes fail.