OStatic

There are loads of terrific general Web publishing tools available these days, but some industries require specific features to meet unique needs. Omeka is a free and open source Web-based publishing platform designed with libraries, higher-level learning institutions, and museums in minds. Funded by philanthropic organizations and licensed under the GPL, Omeka makes launching an online exhibition as easy as launching a blog and is perfect for groups that don't have IT-specialists on the payroll.

CPAN, the Comprehensive Perl Archive Network, is one of the strongest and most active repositories for open-source libraries around. These libraries, many of which are packaged as Perl objects, do everything from communicate with Amazon's various Web services (including EC2 and S3), to verify credit cards, to manipulate images, to parse XML, to implement SSL. Because of the somewhat chaotic nature of CPAN, many of these functions are implemented in multiple modules. So there are several dozen modules for parsing XML and another few dozen templating systems, for starters.

Want to create modern Web applications? You'll need to use JavaScript. But don't write the JavaScript yourself; use one of the high-quality open-source libraries that let you concentrate on your coding, rather than browser incompatibilities.