Enigma2, the second generation of Enigma software, is an application used in Linux-based Digital Video Broadcasting (DVB-S, DVB-C, DVB-T) receivers or TV set-top boxes and Internet Protocol television receivers. It creates a graphical user interface to control the said devices using a remote control and provides features such as tuning available satellite transponders, cable channels and terrestrial television transmitters (according to available tuners) or accessing material via Internet Protocol television (IPTV), watching a TV program or listening to radio, time shifting, Digital video recorder, streaming media programs to other devices (personal computer, mobile phone), etc. Other features are available through plugins – for example Electronic program guide (EPG), Hybrid Broadcast Broadband TV (HbbTV), access to TV archives and movie databases, playback of multimedia files, viewing photos, etc.

The name Enigma2 is often used to refer to the whole Linux distribution designed for TV receivers containing the Enigma2 application. Sometimes the distribution is called Linux E2 or E2 Linux, but usually it is named after the specific distro or development team – OpenATV, OpenPLi, OpenViX, EGAMI, OpenEight, Black Hole, OpenDroid, PurE2, etc. The distribution was originally developed for Dreambox receivers, but after 2010 a number of manufacturers of similar equipment appeared, such as Formuler, GigaBlue, Octagon, Opticum, Unibox, Vu+, Zgemma, etc.

Devices designed for Enigma2 (i.e. satellite receivers, set-top boxes and IPTV receivers, often simply called boxes) are equipped with one or more DVB-S, DVB-C and DVB-T tuner(s) (unless they are pure IPTV receivers), a Remote control receiver and an Ethernet and/or Wi-Fi network adapter. To receive coded/scrambled programs the box may be equipped with one or more slots for decoding cards. The operating system is usually stored on internal flash memory, whereas to record programs or to play multimedia files a larger, internal or external, hard disk, SSD, USB flash disk or memory card can be used. The device may use Network Attached Storage or a disk volume on a personal computer using Samba or NFS protocol as well. The system is designed to be controlled by a Remote control similar to those used for TV receivers. The TV set usually connected via a HDMI (or SCART) cable works as a multimedia monitor. The device may connect to a home audio system either via TOSLINK or Bluetooth.

The box can be accessed with terminal emulation protocol telnet, ssh, or via FTP. The OpenWebif module implements a web server that allows control of the box from a PC using a web browser. The box can act as a streaming server, streaming material received by its tuners or direct from its hard drive or any mounted device available to it.

Enigma is one of the Graphical user interfaces developed for digital satellite receivers DBox-2 during the TuxBox project in 2000-2001. The development was then continued by Dream Multimedia for their receivers. In 2006 Dream Multimedia released a new open source version of the software called enigma2. Around that time many receiver manufacturers who were competitors of Dream Multimedia started using the software developed by Dream Multimedia without contributing to system development. Dream Multimedia therefore decided not to continue system development as free software and introduced its own Dreambox OS. Currently, there are about 20 teams that develop the enigma2 application, control and maintain their own versions of the distribution for dozens types of devices.

The main feature is displaying the received TV program on the TV screen connected usually using an HDMI cable transferring sound as well. At the same time Enigma2 creates graphical user interface controlled using an infrared remote commander, that displays on the TV screen in the form of menu, dialogues and forms allowing control of all basic settings of the set-top box or the receiver.

Enigma2 features can be extended by various plugins.

Some plugins offers specific features of smart TVs, like