This was meant to be the front-page for the lists of (unofficial, see Disclaimer) instructions available on this project for compiling and cross-compiling OpenFOAM in Linux and other POSIX systems. Unfortunately, this never came to be true. Nonetheless, visit the Installation page at the unofficial OpenFOAM wiki for the instructions provided by the community that uses OpenFOAM technology.
In the page Packages for Compiling you'll find a long list of packages necessary for (cross-)compiling OpenFOAM.
More instructions are yet to be written, but here can already be found:
Older instructions for cross-compiling are available at openfoamwiki.net, in the following pages:
Wiki: CrossCompilingOpenFOAM20
Wiki: Disclaimer
Wiki: Packages4Compiling
Wiki: WikiLobby