ITPerl is a web authoring tool that enables users to add temporal features to intensional web pages. ITPerl adds temporal macros to IPerl, a Perl interface to the C++ intense library. ITPerl combines temporal and default logic with intensional programming. ITPerl is an ideal solution for many time-sensitive and rapidly changing web applications. When developing a site, a user can add a temporal section to a webpage by providing different versions of it and associating each version with a time constraint. When a webpage is requested by a browser, a time point will be sent, as part of the request, to the ITPerl module. This time point is by default the current server time, but can be any time specified by the viewer. ITPerl will then compare the time point with each time constraint. If the time point satisfies more than one time constraint, then ITPerl will choose the best-fit version of the section by finding the most refined constraint. A html page that contains this best-fit version of this section will then be generated and sent back to the browser. ITPerl is easy to use. It provides the user with high level macros that have a simple syntax and that generate temporal codes as cgi files. This frees the user from having to write the complex temporal code himself.