"JBMod was a sandbox modification for Half-Life 2. It came out before Garry's Mod. The idea was that you used the original gravity gun to manipulate objects and create simple welds to hold them together.
When Garry's Mod was first released, it was ridiculed by the newly formed JBmod team and dismissed as a rip-off. In a short amount of time, however, Garry's Mod soon far surpassed JBmod in terms of features and user-friendliness. After a while, it became clear that JBmod was hopelessly playing catch-up to its competitor, and development stuttered to a halt while Garry's Mod continued to grow exponentially. "
* Adnan Zafar - The early physgun/gravity gun rotate code
* Helk - Can really bore you to death about VGUI - but comes in useful.