Faxfrontend is a clean way to print to fax while using a desktop. It provides a GUI interface to print to fax using CUPS to Hylafax. When you print, a box pops up that lets you provide the fax number or find the number to use from the built in address book. It can also run as a standalone application to fax files or just a cover sheet.
Gemeinschaft is a PBX based on Asterisk, MySQL, Apache, and PHP, and designed for high availability and clustering. It provides automatic provisioning for mass deployment, and can handle over 10,000 users. Administration is done via shell scripts or a Web GUI. Hot-desking and mobility are supported. German voice prompts are included. There is a standards-compliant Web GUI with internationalization (and German and English translations). Outbound and inbound routing with full PCRE support is included.