liblo is a lightweight library that provides an easy to use implementation of the OSC protocol. For more information about the OSC protocol, please see:

The official liblo homepage is here:

liblo is portable to most UNIX systems (including OS X) and Windows. It is released under the GNU Lesser General Public Licence (LGPL) v2.1 or later. See COPYING for details.


To build and install liblo, read INSTALL in the main liblo directory. liblo is configured as a dynamically-linked library. To use liblo in a new application, after


you should install liblo with

make install

so that the liblo library can be located by your application.

To build with MS Visual Studio on Windows, first download and run the premake4.exe application in the build directory with an argument describing which IDE you are using. This will generate project and solution files. See build/ for more details.

Building with CMake

If you prefer the CMake build system, support has been added. Instead of the configure step listed in the previous section, create a build directory and initialize CMake:

mkdir ~/build/liblo
cmake ~/source/liblo/cmake <more options..>


See examples for example source code for a simple client and two servers:

These examples will work without installing liblo. This is accomplished by a shell script. For example, examples/client_example is a shell script that runs the "real" program examples/.libs/example_client. Because of this indirection, you cannot run example_client with a debugger.


To debug applications using liblo, one option is to include all the liblo source code in the application rather than linking with the liblo library. For more information about this, please see the (libtool manual)1

To compile liblo with debugging flags, use,

./configure --enable-debug


liblo was written to support both IPv4 and IPv6, however it has caused various problems along the way because most of the currently available OSC applications like Pd and SuperCollider don't listen on IPv6 sockets. IPv6 is currently disabled by default, but you can enable it using

./configure --enable-ipv6