Apache is a free and open-source cross-platform web server software.
Mod_dav is an Apache module to provide WebDAV capabilities for your Apache web server. It is an open-source module, provided under an Apache-style license.
PHP is a general-purpose scripting language used for web development.
Prototype is a JavaScript Framework that aims to ease development of web applications.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.