Relaxed Electrophysiological Data Acquisition,
Control, and Stimulation

... enjoy your recordings


relacs is available on Get Relacs at Fast, secure and Free Open Source software downloads , from where you can download a source-code tarball.

For getting the current development version you can download a snapshot from the subversion repository (see below for instructions).


After downloading the source-code tarball, unpack the relacs-xxx.tgz file and change into the relacs directory:

> tar xzvf relacs-xxx.tgz
> cd relacs-xxx

Then read the README and the INSTALL files for more instructions.


You can retrieve a snapshot of the current development version from the Subversion repository on Get Relacs at Fast, secure and Free Open Source software downloads .

Make sure you have subversion installed on your computer:

  sudo apt-get install subversion

Use the following command to retrieve the source tree of the current development version:

  svn co svn:// relacs

This downloads the source files into the directory ./relacs. In most cases, the current version should work and is the preferred version to work with. However, once in a while it is broken. Be warned! You might then give it another try a couple of days later.

Continue with the instructions given in the INSTALL file. You may also want to read the README file.

You can also browse the Subversion repository.

Get Relacs at Fast, secure and Free Open Source software downloads

Supported Platforms

relacs is currently developed under Linux. However, since it is coded in standard C++ and uses the Qt-library for the GUI, a port to Mac OS X and Windows should be possible. However, interfaces to the (data acquisition) devices need to be implemented for each platform as needed. Any help is appreciated!



Phase 1 - Basic development
We have been continually developing and using relacs in our lab since 2000. Features are added as we need them. This development was and still is driven by the very specific requirements of our experiments (see publications).
Phase 2 - Modularization and generalization
Soon we realized that the structure of the program was way to specialized and we started to better modularize the code and to outsource everything that was specific to our experiments as a plugin. As a result the core program is now completely independent of the specific hardware used and independent of the type of experimental setup.
Phase 3 - Technical issues (version 0.9.6)
In 2007 we started to make the program ready to be shared with other people, i.e. setting up GNU autotools and finalizing the interfaces. This is accomplished and you are welcome to join the project and contribute to it.
Phase 4A - New urgent features I (version 0.9.7)
  • Dynamic clamp support
  • Upgrade to Qt4
  • Plugins for current clamp recordings
  • Update the plugins for the electric fish experiments
Have been implemented and run very well in the experiments.
Phase 4B - New urgent features II (version 0.9.8, the current development version)
In this version we reimplemented all name-value pair representations (configuration files, dialogs, table keys, stimulus descriptions, etc., i.e. class Options) to be
  • hierarchical name-value pairs that follow odML standard.
We still need to finish the long awaited
  • data browser.
In addition we started to implement
  • the NIX file format for storing the data together with meta-data.
Phase 5 - Usability (version 1.0, the future)
A program that is highly modular and that compiles and runs flawlessly is still hard to use if the documentation is incomplete and configuration files are not explained. Therefore, the following things need to be accomplished before relacs is easily usable:
  1. Add a tutorial to the documentation
  2. Add various widgets and wizards for configuring relacs:
    • Macro editor
    • Filter and detector setup tool
    • Data acquisition device and channel selection
    This is work in progress.


Please cite relacs in the methods section of your manuscript, if you have acquired a substantial part of your date with relacs. You might also want to provide the name of the RePros you used. Write something like

Data acquistion and closed-loop stimulus generation was controlled by RELACS (, mainly running the protocols X and Y that can be downloaded at www.ZZZ.

relacs is distributed according to the GNU General Public License (GPL):

relacs - Relaxed ELectrophysiological data Acquisition, Control, and Stimulation

Copyright (C) 2002-2017 Jan Benda <>

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

relacs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <>.

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