Kmscon

Kmscon is a userspace virtual console developed by David Herrmann as an alternative to the Linux kernel's built-in terminal. It leverages the KMS driver for output, supports multiseat functionality, and uses XKB for keyboard input along with UTF-8 output. While its primary dependency is udev, it optionally integrates with Mesa for hardware acceleration and Pango for enhanced font rendering. Unlike the traditional Linux console, Kmscon allows full Unicode character display without encoding restrictions.

Development of Kmscon ceased in March 2015, followed by the termination of its successor, systemd-consoled, in July 2015. The project aimed to address limitations of the legacy VT system, which lacked native multiseat support and limited active sessions to a single VT at any time. Kmscon introduced out-of-the-box multiseat capabilities but required specific configurations for simultaneous use across multiple seats.

The terminal emulator's state machine library, libtsm, was extracted from Kmscon in 2013 and made available separately, alongside wlterm, a Wayland-based terminal example. Inspired by Jesse Barnes' 2011 blog on userspace DRM implementation, David Herrmann initially developed Kmscon to reduce reliance on kernel framebuffer and VT subsystems.

Kmscon's legacy includes contributions to terminal emulation and display technologies, reflecting efforts to modernize console functionality in Linux environments.