Similar to Fluxbox

Aptana

Ark (software)

Arora (web browser)

Audacious (software)

Aufs

AutoKey

AV1

Avahi (software)

Avidemux

AviSynth

Axiom (computer algebra system)

Bc (programming language)

Berkeley DB

Berry Linux

Binary File Descriptor library

Bhyve

BIRT Project

Bochs

Boo (programming language)

Botan (programming library)