The online help for IDL (since IDL 6.2) is plain HTML normally displayed using the “IDL Assistant.” It would be convenient if ITTVIS would publish it on their website. Then people in the IDL community could say things like: “Check out the CONGRID routine.” Fortunately, the online help for IDL 6.3 is available on NASA’s Astrolib. I noticed it this spring and I’ve been waiting to see if it would be taken down. It has survived so far, so I’m going to try to use references to the online help in my posts in this website and on the comp.lang.idl-pvwave usenet group.

UPDATE 3/20/2016: Online help has been hosted online by Harris (then Exelis VIS) since October 2012.