Fast, portable and opinionated build system

jbuilder is a build system that was designed to simplify the release
of Jane Street packages. It reads metadata from "jbuild" files
following a very simple s-expression syntax.

jbuilder is fast, it has very low-overhead and support parallel builds
on all platforms. It has no system dependencies, all you need to build
jbuilder and packages using jbuilder is OCaml. You don't need or make
or bash as long as the packages themselves don't use bash explicitely.

jbuilder supports multi-package development by simply dropping multiple
repositories into the same directory.

It also supports multi-context builds, such as building against
several opam roots/switches simultaneously. This helps maintaining
packages across several versions of OCaml and gives cross-compilation
for free.