Ach is an Inter-Process Communication (IPC) mechanism and library. It is especially suited for communication in real-time systems that sample data from physical processes. Ach eliminates the Head-of-Line Blocking problem for applications that always require access to the newest message. Ach is efficient, robust, and formally verified. It has been tested and demonstrated on a variety of physical robotic systems. Source code for Ach is available under an Open Source BSD-style license.

./configure && make && make install

See the INSTALL file for details.

Alternatively, if you are using Debian or Ubuntu, you can use the golems.org APT repo.

1. Add the following to /etc/apt/sources:

   deb http://code.golems.org/debian squeeze golems.org

(substitute the codename for your distribution in place of squeeze, e.g. wheezy, precise)

2. sudo apt-get update && sudo apt-get install libach-dev ach-utils

3. sudo dpkg-reconfigure ach-utils

• Manual: ./doc/manual/ach-manual.html and http://golems.github.com/ach/manual
• API docs: http://golems.github.com/ach/api
• Man Pages: ./doc/man and http://code.golems.org/pkg/ach/man
• Example Code: ./src/ach-example.c
• Tech Report: http://www.golems.org/node/1526

Language bindings are included for Common Lisp and Python.

• Common Lisp bindings use CFFI and can be loaded with ASDF.

• Python bindings are a C extension modules and a Python module 'ach'. This can be installed either via make install or via Python's distutils/pip.

See the INSTALL file for details.

Ach has been formally verified using the SPIN model checker. This formal model is included in the source distribution under the ./spin/ directory.