Sort of a chicken and egg thing. JavaScript initially was only available on Netscape in extremely late 1995. MS implemented their own version as JScript with M

Sort of a chicken and egg thing. JavaScript initially was only available on Netscape in extremely late 1995. MS implemented their own version as JScript with MSIE 3.2 IIRC in 2Q-3Q 1996. The other extant browsers didn't implement it at all. Through 1996 and 1997 the only real stuff you could do with JS was the intersection between JavaScript and JScript. Given the average speed of the consumer internet was something between 33kbps and 53kbps, we were already pushing the limits of how long people would wait for a page to load before hitting esc and moving on to something else. To be successful a client side language had to be multiplatform / multibrowser from the start and none of the alternatives were. IBM tried putting Rexx in WebExplorer (I don't even know if that version escaped from IBM internal use). I vaguely recall some sort of extension on whatever shipped on the SGI Indy in 1996 but I don't remember if that was just SGI implementation of JavaScript with Indy enhancements or something entirely different. Doing anything more sophisticated than simple dhtml menus or form validation was just impractical until broadband became more widespread around 2001-2002. There's a reason web 2.0 happened when it did, it wasn't just the enhancements to JavaScript & the DOM & browsers but the average user started to have access to 1Mbps DSL and cable modems.