Does the JSTL come with Tomcat, or does it require a separate download?
Separate.
Can the JSTL be installed only as part of a web application, or can it also be part of the "global" libraries that Tomcat has available, such as those in the common/lib directory?
You can put the jars there, but each web app still needs the appropriate declarations.
Could any conflicts arise if JSTL 1.1 were in the common/lib, but then a web app included JSTL 1.0?
Haven't tried it, but I can't think of any obvious problems.
I understand that Tomcat 5.x supports JSP 2.0, and so would also support JSTL 1.1.
Correct.
Is there any way to run JSTL 1.1 on Tomcat 4.x?
No. JSTL 1.1 requires a container that processes EL.
[ September 18, 2004: Message edited by: Bear Bibeault ]