OSCache allows for fine-grained dynamic caching of JSP content (resulting in massive speed increases) and better error tolerance for JSP pages. This 1.1 release is the first that only requires Servlet 2.2 so it should now run in any servlet container.

Masses of bug fixes and new feature additions means this is moving past 'experimental' software into the realm of 'must have' software! ;)

OSCache solves two fundamental problems of all dynamic sites:

- Caching Dynamic Content - Dynamic content must often be executed in some form each request, but sometimes that content doesn't change every request. Caching the whole page does not help because parts of the page change every request. OSCache solves this problem by providing a means to cache sections of JSP pages.

- Error Tolerance - If one error occurs somewhere on your dynamic page, chances are the whole page will be returned as an error, even if 95% of the page executed correctly. OSCache solves this problem by allowing you to serve the cached content in the event of an error, and then reporting the error appropriately.

Find out more here : http://www.opensymphony.com/oscache

This looks similar to a preview feature thats currently shipping with WebSphere Advanced Server 3.5.3. It offers caching of JSPs now albeit in preview/beta form.

Oracle and iPlanet (although memoization isn't quite the same) offer similar features also. Anyone know if BEA have a similar feature?

WebLogic 5.1 SP6 provides a cache tag, see Custom WebLogic JSP Tags (Cache, process, repeat.

OSCache is actually very similar to this except that it also includes two extra features:
- caches can be written to disk to be persistent across server restarts (useful if you have a huge amount of cached data updated infrequently)
- it provides error tolerance by allowing you to serve the cached data if an exception is thrown (for example your db goes down)

Of course it's released under LGPL so you can hack at it yourself ;)

BTW 1.2 is now out (fixed a bug in 1.1)

Coldjava has Cache tag also. See
http://coldjava.hypermart.net/jsp.htm

As far as I know, the WL Advanced server caching caches and entire JSP page. I wrote a ServletFilter (Servlet 2.3 spec) that does this as well but it's not nearly as useful as very rarely these days is an entire page the same for every request.