(Gosu supposedly also works on FreeBSD if you adapt these steps.)

To install Gosu in any form, you will need the following packages build-essential, freeglut3-dev, libfreeimage-dev, libgl1-mesa-dev, libopenal-dev, libpango1.0-dev, libsdl-mixer1.2-dev, libsdl-ttf2.0-dev, libsndfile-dev, libxinerama-dev

Copy-and-pastable command line for Ubuntu, last tested on 10.10, should work across all versions:

# For C++
sudo apt-get install build-essential freeglut3-dev libfreeimage-dev libgl1-mesa-dev libopenal-dev libpango1.0-dev libsdl-mixer1.2-dev libsdl-ttf2.0-dev libsndfile-dev libxinerama-dev
# To install the gem for Ruby 1.8
sudo apt-get install build-essential freeglut3-dev libfreeimage-dev libgl1-mesa-dev libopenal-dev libpango1.0-dev libsdl-mixer1.2-dev libsdl-ttf2.0-dev libsndfile-dev libxinerama-dev ruby1.8-dev rubygems
# To install the gem for Ruby 1.9.1/1.9.2(?)
sudo apt-get install build-essential freeglut3-dev libfreeimage-dev libgl1-mesa-dev libopenal-dev libpango1.0-dev libsdl-mixer1.2-dev libsdl-ttf2.0-dev libsndfile-dev libxinerama-dev ruby1.9.1-dev rubygems

Copy-and-paste command line for Fedora, last tested on 17, should work across all versions:

# For C++
sudo yum groupinstall --assumeyes "Development Tools"
sudo yum install --assumeyes freeglut-devel freeimage-devel mesa-libGL-devel openal-devel pango-devel SDL_mixer-devel SDL_ttf-devel libsndfile-devel libXinerama-devel
# To install the gem for Ruby 1.9
sudo yum groupinstall --assumeyes "Development Tools"
sudo yum install --assumeyes freeglut-devel freeimage-devel mesa-libGL-devel openal-devel pango-devel SDL_mixer-devel SDL_ttf-devel libsndfile-devel libXinerama-devel ruby-devel rubygems

Please check how to install all this software if you are on a different distribution.

If you are only interested in using Gosu with the Ruby programming language, you can install it as a Ruby gem via sudo gem install gosu. You need to install the packages from above.

Afterwards, gem install gosu should work.

To compile Gosu, cd into the linux subdirectory and run:

./configure
make

There is a deprecated make install command that will work for C++, but as most Linux distributions are using a package manager nowadays we recommend copying the resulting linux/libgosu.a file to your game's directory manually.

(The following assumes that you have installed Gosu system-wide via sudo make install. If not, you will have to add paths as necessary.)

You have to compile with `gosu-config --cxxflags` and `gosu-config --libs`, so a simple Makefile could look like this:

OBJS = main.o player.o
CXXFLAGS += `gosu-config --cxxflags`
LIBS = `gosu-config --libs`

myGame: $(OBJS) libgosu.a
        g++ -o myGame $(OBJS) libgosu.a $(LIBS)