OpenClass is a simple solution for class control. It provides multicast screen projection (sending the teacher's screen to all of the students), student attention requests (blocking student activities and asking them to look at teacher), viewing of all student screens at once, direct messaging to students, file and URL sharing, computer shutdown, access control for specific classes, and support for multi-seat configurations and multiple clients per machine. For students it provides automatic teacher discovery via broadcast, "raise hand" functionality, and automatic handling of network saturation and disconnection events.
Billion PBX is IP phone system that uses the SIP protocol. In addition to voice calls it supports call forwarding, voicemail, callback, and much more, and features simple installation and configuration, reliability, low hardware requirements, and a flexible pricing policy. Its main features are subscriber registration by SIP Registrar and RAS protocols, call routing by SIP and H.323, call authorization, subscriber self-service, Call Data Records (CDR), embedded rating and billing, integration with external billing systems, NAT traversal, IVR, report generation, and a convenient administrative Web interface allowing remote management.
Billion Softswitch works as a switchboard in SIP/H.323 VoIP networks, proxying both signalling and media streams while performing cross-protocol conversion and even media stream transcoding. It integrates advanced call routing features as well as embedded compact billing system. It supports subscriber registration by SIP Registrar and RAS, call authorization, call data record (CDR) list maintenance, external billing system interfaces, NAT/firewall support, and report generation, and is easy to install and maintain.
gtk-screenshot is a program for taking screenshots. It captures the screen or a window and saves the image in the PNG format. It is similar to gnome-screenshot but it's not a GNOME application. All parameters may be specified on the command line, or the application can be graphicaly driven.