MSDN used HTML4 frames for a long time (afaik until ca. 2006). The left side bar (left frame) with the tree was a Java applet and with the relauch in 2000 a DHT

MSDN used HTML4 frames for a long time (afaik until ca. 2006). The left side bar (left frame) with the tree was a Java applet and with the relauch in 2000 a DHTML page. The tree was expanded using DHTML (a marketing term that describes HTML with heavy Javascript usage). Javascript was used to change the visibility of DOM nodes (tree). That data of the TOC tree was loaded as XML (XMLHTTP). Article that explains the MSDN server backend (1999): https://web.archive.org/web/19990505061257/http://msdn.microsoft.com/msdn-online/MSDNchronicles.asp https://web.archive.org/web/19990505061257/http://msdn.micro... Before that relaunch in 2000, the MSDN library used (MS) Java for the left side bar (TOC tree): https://web.archive.org/web/19990423231040/http://msdn.microsoft.com/library/default.htm https://web.archive.org/web/19990423231040/http://msdn.micro... The DHTML version of MSN library (2000): https://web.archive.org/web/20000510200809/http://msdn.microsoft.com/library/default.asp https://web.archive.org/web/20000510200809/http://msdn.micro... , the 2001 version works: https://web.archive.org/web/20011108064645/http://msdn.microsoft.com/library/default.asp https://web.archive.org/web/20011108064645/http://msdn.micro... XML toc tree data: https://web.archive.org/web/*/http://msdn.microsoft.com/library/msdn-online/shared/xmltoc/inc/toc.inc https://web.archive.org/web/*/http://msdn.microsoft.com/libr... (sadly not archived)