Similar to MEncoder

Aufs

AutoKey

AV1

Avahi (software)

AviSynth

Axiom (computer algebra system)

Berkeley DB

Berry Linux

Binary File Descriptor library

Bhyve

Blackbox

Bochs

Boo (programming language)

BootX (Apple)

Botan (programming library)

Brotli

BSD libc

Budgie (desktop environment)