So the early returns are already coming in, and it seems that an awful lot of systems will be lacking one or more required packages to get the codebase to compile.
So listen up people. Read and know.
If you get a bunch of spam starting off complaining that gd.h is missing, then you need the GD Development package.
yum install gd-devel
This will resolve the necessary dependencies to make it work. This package is required for the overland code to function. And before you ask. No. It's not being made optional. So just don't.
apt-get install libgd2-dev ( if that doesn't work, try: apt-get install libgd2-xpm-dev )
For MySQL support, this is less clear as to what you'll require. But chances are you'll need the MySQL server and a MySQL client, along with the MySQL development packages. If you're in a hosted environment, chances are high you already have this provided to you.
How to obtain these varies widely by system.
For recent copies of Fedora, it looks like all you'll need are:
yum install mysql
yum install mysql-devel
yum install mysql-server
For Ubuntu systems:
apt-get install libmysqlclient15-dev
Not sure what the package name for the server is but without it you're probably not going to get far.
Cygwin users are out of luck. There is no MySQL support available, so you'll just need to skip it.