udp_copy2 consists of two executables, udp_send2 and udp_recv2, implementing plain text non-interactive data transfer over UDP/IPv4 with a preset transfer rate. On lossy links, it yields better throughput than TCP-based transfers. It may also be used for smooth user space throttling. It dedicates a mode to SNAT/MASQ so the receiver can initiate transfer from behind a firewall. It features a very precise user space packet scheduler. It handles SIGSTOP in a rational way. It only transfers in one direction for one invocation. It needs and uses no synchronous I/O multiplexing. Shell access is required on both ends. The package also contains the auxiliary multi-threaded tool "bigpipe", which can be used to reduce pipeline latency.
Pak transfers multiple, possibly very big, regular files between possibly different hosts you have shell access to. It transmits segment IDs instead of file names and uses on-the-fly Blowfish-CBC encryption while being absolutely restartable with practically no loss of data already transmitted. Encrypted pak streams can be stored in intermediary regular files on untrusted hosts. Several stored pak streams, even truncated ones, can be merged for re-piping without decryption. Integrity is never checked. File offsets of any magnitude are supported via recompilation (the default width is 64 bits). Either UNIX 95 or UNIX 98 conformance is required and sufficient.
lxz aims to create xz-compatible compressed files, utilizing multiple threads and liblzma. It was forked from lbzip2-0.23 and inherited the same internal structure. It supports compression only (basic features), and will lose its raison d'etre as soon as xz itself gets multithreading support.