Sourceer is a easily and highly configurable single-file script to browse directories and view source code of .php, .htm, etc., files. Among other things, it can be useful for presenting source code of software projects (a much simple alternative to Trac, PHPDoc, Doxygen, SVN / CVS systems, etc.). Sourceer produces XHTML 1.0 Strict-compliant output whose page layout and CSS-styling can be easily edited. Configurable parameters include optional IP address- or password-based authentication, ability to browse above the root level directory, file-types (like .php and .js) whose source code is viewable, syntax-highlighting of source code through external means like Geshi, and protected files and directories. Sourceer can be used independently or can be easily included in other systems as a plug-in, include, PHP class, etc.