~$ apt-cache show libgl1-mesa-swx11-i686
Package: libgl1-mesa-swx11-i686
Priority: extra
[...]
Description: Mesa OpenGL runtime [i686 optimized]
Mesa is a 3-D graphics library with an API which is very similar to
that of OpenGL. To the extent that Mesa utilizes the OpenGL command
syntax or state machine, it is being used with authorization from
Silicon Graphics, Inc. However, the author makes no claim that Mesa
is in any way a compatible replacement for OpenGL or associated with
Silicon Graphics, Inc.
.
This library provides a pure software rasteriser; it does not provide
a direct rendering-capable library, or one which uses GLX. For that,
please see libgl1-mesa-glx.
.
[...]