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This is the Abstract Library for Parallel Search (ALPS), the abstract base layer of the COIN-OR High Performance Parallel Search framework.


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A COIN-OR Project

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Latest Release

This file is auto-generated from config.yml using the generate_readme script. To make changes, please edit config.yml or the generation scripts here and here.

Welcome to Alps, (Abstract Library for Parallel Search). Alps is a framework for implementing parallel graph search algorithms. Its methodology generalizes many of the notions of an LP-based branch-and-bound algorithm, allowing the implementation of a wide range of algorithms with a simplified interface. Alps implements the search handling methods required for implementing large-scale, data-intensive parallel search algorithms, such as those used for solving discrete optimization problems. It is the base layer of the CHiPPS (COIN High Performance Parallel Search) library hierarchy that will includes a library for solving mixed integer linear programs (BLIS).

Alps is written in C++ and is released as open source under the Eclipse Public License 2.0.

It is distributed under the auspices of the COIN-OR Foundation

The Alps development site is


Code: DOI



Windows Builds

Linux and MacOS Builds


Docker image

There is a Docker image that provides Alps, as well as other projects in the COIN-OR Optimization Suite here


For newer releases, binaries will be made available as assets attached to releases in Github here. Older binaries are archived as part of CHiPPS-BLIS here.

Due to license incompatibilities, pre-compiled binaries may lack some functionality. If binaries are not available for your platform for the latest version and you would like to request them to be built and posted, feel free to let us know in the discussion formum.


Source code can be obtained either by

  • Downloading a snapshot of the source code for the latest release version of Alps from the releases page.
  • Cloning this repository from Github or
  • Using the coinbrew script to get the project and all dependencies (recommended, see below).

Below is a quick start guide for building on common platforms. More detailed build instructions are here.


Alps has a number of dependencies, which are detailed in config.yml. Dependencies on other COIN-OR projects are automatically downloaded when obtaining the source with coinbrew. For some of the remaining third-party dependencies, automatic download scripts and build wrappers are provided (and will also be automatically run for required and recommended dependencies), while other libraries that are aeasy to obtain must be installed using an appropriate package manager (or may come with your OS by default).

BUILDING from source

The quick start assumes you are in a bash shell.

Using coinbrew

To download and build Alps from source, execute the following on the command line.

chmod u+x coinbrew
./coinbrew fetch Alps@master
./coinbrew build Alps

For more detailed instructions on coinbrew, see The coinbrew script will fetch the additional projects specified in the Dependencies section of config.yml.

Without coinbrew (Expert users)

  • Download the source code, e.g., by cloning the git repo
  • Download and install the source code for the dependencies listed in config.yml
  • Build the code as follows (make sure to set PKG_CONFIG_PTH to install directory for dependencies).
./configure -C
make test
make install


For configuration and compilation of the parallel version, the user has to specify the location of MPI with options --with-mpi-cflags, --with-mpi-lflags, MPICC, and MPICXX.

./coinbrew build Alps --enable-static --disable-shared --with-mpi-cflags="$\(pkg-config --cflags mpi\)" --with-mpi-lflags="$\(pkg-config --libs mpi\)" MPICC=mpicc MPICXX=mpiCC


To build example codes (ABC and KNAP), configure and build as above. Switch into the appropriate subdirectory in the source distribution and type make.

Doxygen Documentation

If you have Doxygen available, you can build a HTML documentation by typing

make doxygen-docs

in the build directory. If Alps was built via coinbrew, then the build directory will be ./build/CHiPPS-ALPS/master by default. The doxygen documentation main file is found at <build-dir>/doxydoc/html/index.html.

If you don't have doxygen installed locally, you can use also find the documentation here.

Project Links


  1. Configurations - Serial: Well tested. - LAMMPI: Well tested. - MPICH: Well tested.

  2. Applications (See INSTALL) - Abc: Alps Branch and Cut (A simple generic MILP solver): Well tested. - Knap: Knapsack solver: Well tested.


Source Code:

Yan Xu ( Aykut Bulut ( Ted Ralphs (, Project Manager

Original Conceptual Design:

Yan Xu ( Ted Ralphs (, Project Manager Laci Ladanyi ( Matt Saltzman (


This is the Abstract Library for Parallel Search (ALPS), the abstract base layer of the COIN-OR High Performance Parallel Search framework.








Contributors 4