LXE -- Linux cross-toolchain environment.
This project may be useful when you need to build your applications for a few old GNU/Linux distributions and you do not want to manage a number of chroot environments and/or use a hypervisor (like QEMU, VirtualBox or VMware) with full operating systems. It requires significantly less amount of disk space and CPU power. And it is much simpler and faster than Open Build Service, Jenkins, etc.
There are no reported vulnerabilities