When using tag libraries within a WAR or Web Module, be sure to include an Import-Bundle or Import-Library for the tag library bundle(s). This will ensure that your module can see the TLD definition and implementing types. For example, to use the Apache implementation of JSTL, add the following to your bundle's /META-INF/MANIFEST.MF:

Import-Bundle: com.springsource.org.apache.taglibs.standard;version="1.1.2"