Zyan Communication Framework simplifies development of distributed applications. It works on Windows, Linux, Mac OS, and Android platforms via .NET or Mono runtimes. It features LINQ support for three-tier applications, full duplex TCP support, traffic, compression, and encryption, transparent support for events and EBC (event-based components), and Windows and LDAP authentication support.
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.