BleachBit deletes junk to recover disk space and maintain privacy. It rids your system of old junk including cache, Internet history, temporary files, unused locale files (better than localepurge), logs, and cookies. Designed for Linux systems, it wipes clean 50 applications including Adobe Reader, Bash, Firefox, Flash, OpenOffice.org, Opera, Real Player, Skype, and more. It shreds files so that they cannot be recovered, and it wipes free disk space to hide insecurely deleted files. It offers both a simple PyGTK GUI and a command line interface for automation.
MojoMojo is a Web2.0 wiki with AJAX live preview, hierarchical structure, tags, diffs, pluggable syntax, permissions/ACL, attachments, RSS feeds, a photo gallery, edit conflict resolution via 3-way merge, themes/skinning, localization, built-in full-text search, and a reverse index. Since it's built on top of the Perl Catalyst Web framework, MojoMojo supports any Web server, and includes its own standalone one. It also support any database backend supported by the DBIx::Class ORM, and has been successfully tested with PostgreSQL, SQLite, and MySQL.
jPDFFields is a Java library for working with interactive PDF forms in both AcroForm and XFA formats. It allows your application to get and set field values, and can import and export to the FDF, XFDF, and XDP formats. It can also "flatten" fields in a document. (Flattening is the process of merging the fields into the PDF content layer so the information is retained, but as static PDF content.) jPDFFields is built on top of Qoppa's proprietary PDF technology, so it is 100% Java and does not require any third party software or drivers.