libencio is a library providing a stdio-like interface for reading and writing of encrypted files (in MCrypt format only for now). Additionally, it provides full support for fseek()-like random read access of encrypted data. This allows one to operate on encrypted files as if they were ordinary, cleartext files. It could be used to provide MUAs with a layer to transparently handle encrypted attachments, as a backend to ffmpeg or mplayer to directly play encrypted files, or in combination with tar for encrypted backups. It uses libmcrypt and libmhash for encryption and hashing algorithms.
udpfwd is a stateful userspace UDP port forwarder that can accomplish SNAT/DNAT. It listens for packets received on a given port, changes their source IP addresses to the address of the local host ("SNAT"), and forwards them to the destination (dest_ip:dest_port) from a randomly chosen local sending port. Once chosen, the source_ip:source_port:send_port triplet is unique, allowing for connection tracking. Conversely, when a packet is received on send_port, its destination is changed to source_ip:source_port ("DNAT"), and forwarded onwards.