ALSA
The Advanced Linux Sound Architecture.
ALSA, the Advanced Linux Sound Architecture, is the kernel-level sound subsystem on Linux. It provides drivers for most consumer and professional sound cards, plus a userspace library (alsa-lib) for direct hardware access and a small set of command-line utilities (aplay, arecord, amixer, alsamixer) for playback, recording, and mixer control.
Higher-level audio servers — PulseAudio historically, PipeWire on most modern systems, and JACK for professional audio — sit on top of ALSA. Applications usually go through one of these servers rather than talking to ALSA directly, which lets multiple applications share a single sound card and gives the user per-application volume control.
Jaroslav Kysela started ALSA in 1998 to replace the older OSS driver layer that had become proprietary. ALSA was merged into the Linux kernel in version 2.6 (2003) and has been the standard kernel sound layer ever since. The userspace components are LGPL-licensed; the in-tree kernel drivers are GPL-2.0.
License: GPL-2.0-or-later (kernel) / LGPL-2.1+ (userspace)
Category: System
Website: https://www.alsa-project.org/
Install
Built into the Linux kernel; userspace utilities: Debian/Ubuntu: sudo apt install alsa-utils Fedora/RHEL: sudo dnf install alsa-utils Arch: sudo pacman -S alsa-utils
Authors
- Jaroslav Kysela and ALSA contributors