NanoHttpd is a lightweight HTTP server designed for embedding in other applications. It's only one Java file, in two "flavors", one strictly Java 1.1 compatible, and one at "current" standards. It supports GET, POST, PUT, HEAD and DELETE requests, and supports file uploading with very small memory overhead. Temp file usage and the threading model are easily customized.
blists is a Web interface to mailing list archives. It works off indexed mbox files. It includes two programs: bindex and bit. bindex generates or updates the index file (incremental updates are supported). bit is a CGI/SSI program that generates Web pages on the fly. Both programs are written in C and are very fast.
linux_ics is designed to make the process of sharing an Internet connection from a Linux computer easier for the average user. It handles configuring the interfaces, setting up NAT, and optionally running a DHCP server. In addition to Ethernet, linux_ics can also share an Internet connection over a WiFi interface in either ad-hoc or master mode.
Aftpd is an FTP server for anonymous access designed for Unix-like operating systems. It uses an asynchronous model of connection processing and provides service for all users within a single process; can use multiple threads to run more efficiently on multi-core systems, with each thread serving multiple clients simultaneously; uses effective mechanisms of transferring files, minimizing copying of data in RAM (sendfile or a combination of the system calls mmap/writev); uses effective event notification schemes (kqueue on FreeBSD and epoll on Linux); uses poll or select in older systems; and supports IPv6. For safety, it works as an unprivileged user and uses chroot.
LibHTP is a security-aware parser for the HTTP protocol and the related bits and pieces. That can mean many things, but the only scenario in which LibHTP has been tested so far is the one when you need to parse a duplex HTTP stream that you have obtained by passively intercepting HTTP traffic. Just feed the raw TCP stream to LibHTP and it will do the rest.