mod_rewrite in a subfolder

It's not clear what you are trying to rewrite here. It would help if you would post a few detailed examples, like

Rewrite from /widget/ or /widget to /widget?query=abc
Rewrite from /widget/foo/ or /widget/foo to /widget/foo?query=abc

I attempted to derive this from your posted rules, but only the second one has correct syntax; The others are missing either the substitution URL or a space between the pattern and substitution URL. So I don't know what you are trying to accomplish.

Jim

RewriteEngine On
RewriteRule ^([^/]+)/(.+)$?var1=$1&var2=$2
RewriteRule ^([^/]+)$ $1/
RewriteRule ^([^/]+)/$?var1=$1 

I am attempting to get

www.com/widget/foo/bar/ from?var1=foo&var2=bar

sometimes only 'foo' will be present (with or without trailing slash) and sometimes both 'foo' and 'bar' will be present (with or without trailing slash). Then if neither 'foo' nor 'bar' are present obviosuly the widget folder gets shown. At present if neither foo nor bar are present then the url shows

www.com/widget/?var1=C:&var2=Inetpub/wwwroot/site/widget

OK, if I understand what you're trying to do, this should work better:

RewriteEngine On
RewriteRule ^([^/]+)/(.+)$ /widget/?var1=$1&var2=$2 [L]
RewriteRule ^(.+)$ /widget/?var1=$1 [L]

If this shows the same problem, then you've got some code in a higher .htaccess file or in httpd.conf that is incorrect -- It appears to be appending the value of DOCUMENT_ROOT to the URL if the trailing slash is missing. Also, make sure you've got content negotiation disabled (by using Options -MultiViews if necessary).

Jim

They seem to be generating the same problems as I was having.

This code

RewriteEngine On
RewriteRule ^([^/]+)/(.+)$?artist=$1&album=$2 [L]
RewriteRule ^([^/]+)/([^/]+)$?artist=$1&album=$2 [L]
RewriteRule ^([^/]+)$ $1/ [L]
RewriteRule ^([^/]+)/$?artist=$1 [L]

seems to work for everything except www.com/widget which redirects to www.com/widget?var1=C:&var2=Inetpub/wwwroot (on windows) and produces a 500 error (on Linux) - NB. the site sits as a subdomain of another domain and has its own unique domain name.