FTPL (FakeTime Preload Library, aka libfaketime) intercepts various system library calls and tricks programs of your choice into seeing a faked system time without having to change the time system-wide. This can be used for running legacy software with Y2K bugs, testing software for year-2038 compliance, debugging time-related issues such as expired SSL certificates, and using software that ceases to run outside a certain time frame. The faked time can be specified either absolutely or relative to the real current time, and optionally also affects file timestamps. The faked clock continues to run, but can optionally be frozen, slowed down, or made faster. A wrapper script "faketime" simplifies the usage, similar to tools such as fakechroot.
PRoot is a user-space implementation of "chroot", "mount --bind", and "binfmt_misc". This means that users don't need any privileges or setup to do things like using an arbitrary directory as the new root filesystem, making files accessible somewhere else in the filesystem hierarchy, or executing programs built for another CPU architecture transparently through QEMU user mode. Also, developers can add their own features or use PRoot as a Linux process instrumentation engine thanks to its extension mechanism. Technically, PRoot relies on "ptrace", an unprivileged system call available in every Linux kernel.
dabba is a set of distributed network monitoring tools for Linux. Its main use is to gather or scatter actions on a network such as traffic capture, replay, generation, or monitoring. It was inspired by the Dabba Walla system in Mumbai where meals are regrouped and dispatched throughout the city with a high efficiency rate, every day of the year. The project has three main components: libdabba, a low-level zero-copy network library, dabbad, a multi-threaded task manager and IPC query processor, and dabba, a CLI for communicating with dabbad and submitting tasks.
systemd is a system and service manager for Linux, compatible with SysV and LSB init scripts. It provides aggressive parallelization capabilities, uses socket and D-Bus activation for starting services, offers on-demand starting of daemons, keeps track of processes using Linux cgroups, supports snapshotting and restoring of the system state, maintains mount and automount points, and implements an elaborate transactional dependency-based service control logic. It can work as a drop-in replacement for sysvinit.