is there a limit to the number of &var's you can have in any 1 session?

In Release 5 there is no limit to the number of Amper variables. In prior releases there was a limit of 400.

according to tech support, there is a limit of 512 with some 25 or so taken up by focus.
and i'm in release 5.

I'm in 5.2 and have a fex that has approximately 1250 variables in it, although many are looped and I can't confirm that I've ever taken all 1250. Still, though, I've not run into any issues so far on this.

the limit i'm slamming into is 320 &vars from a form. May be an html-caused restriction. vars are 7 chars long in name and 3 chars long in varlength, so that's 3200 bytes. More experimentation will figure this out.

Seems Gerry's right on this one.

Just created 100k amper variables and it worked out fine, but it was very slow 3minutes which looks like the old bugbear of MODIFY no hashing on the symbol table.

Susannah,

For WebFocus it's now memory dependant, however for your browser it's not.

Microsoft's statement about all browser versions from 4.0 thru 7

"Microsoft Internet Explorer has a maximum uniform resource locator (URL) length of 2,083 characters. Internet Explorer also has a maximum path length of 2,048 characters. This limit applies to both POST request and GET request URLs"

If you are using post and not get to submit the form then this should not be an issue
as variables in post go via the host header and not the URL but you need to watch that 2048 char limit.