eINIT is an alternative init system. It's quite fast, since it can potentially be used without the help of any scripting at all, but it is still flexible and extremely modular. The focus is on speed and parallelisation, mostly with embedded devices and low-downtime servers in mind, and benchmarks do suggest that it's doing a fairly good job at that. It compiles cleanly (and should thus work, provided someone writes appropriate modules) on Linux, FreeBSD, and Darwin/Mac OS X.
TFTP Server is a multi-threaded TFTP server, allowing any number of clients to connect simultaneously. It supports tsize, blksize, and interval options, PXE boot, and can be run standalone or as a daemon. Port ranges can be specified to work across firewalls. There is also a single port version, for situations where additional ports cannot be opened.
HeavenOS is an original, alternative 32-bit operating system for Intel 80386 compatible processors. It is made with NASM (The Netwide Assembler), and is not intended to compare to modern operating systems, but to try to get the best features and discover better ways to do things. It is intended to be a simple and pratical platform for development, running with a small amount of code.
waitfordevice is a tool that waits for a device to become available. One can use this, for example, when waiting for a USB device to be fully ready after modprobing the USB subsystem (which runs async). This tool can be used in startup scripts or other scripts that need to use a device. It is better guaranteed to work (and more efficient) than using a couple of sleep statements.