DynaBlocks was an early ROBLOX name. Jim Stevens registered this site on December 12, 2003. Before ROBLOX got its name, it was named DynaBlocks between 1997 and 2004. In 2003, DynaBlocks' url was GoBlocks.com but was later changed to DynaBlocks.com. It was later renamed to ROBLOX in late 2004, due to DynaBlocks being "too hard" to remember. dynablocks.com, dynablox.com or dynablock.com, redirects to roblox.com, and "Waiting for web.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.
Here is a fan-made recreation of the 2004 site here.