Did you add corresponding lines to web.xml?
<jsp-config>
<taglib>
<taglib-uri>http://java.sun.com/jsp/jstl/core</taglib-uri>
<taglib-location>/WEB-INF/c.tld</taglib-location>
</taglib>
</jsp-config>
Also you should place jstl.jar and standard.jar to ${Catalina_HOME}/common/lib
and you should place c.tld to Application/WEB-INF directory
These steps are not necessary:
>add corresponding lines to web.xml?
>tld to Application/WEB-INF directory
Actually all that is required is to put the jstl.jar and standard.jar in the web application classpath. The tld is bundled in the jar.
>you should place jstl.jar and standard.jar to ${Catalina_HOME}/common/lib
While it works in common/lib, it is not necessarily the best place for it.
/common/lib is the place to put libraries required by both the Tomcat engine, and your web apps. JSTL is not one of those. I would prefer /shared/lib.
Putting it in WEB-INF/lib makes it available to just the one web app.
Putting it in /shared/lib makes it available to all your web applications.