I've written real time (stock exchange like) web applications in the 90s using Java Applets (also ActiveX for IE browser). Before that I wrote even simpler one

I've written real time (stock exchange like) web applications in the 90s using Java Applets (also ActiveX for IE browser). Before that I wrote even simpler one (no Applets or ActiveX) as it has relied on server push which was supported by Netscape browser only and it had a bit less functionality. On back end I just wrote custom webserver.