Divmod Vertex is an implementation of Q2Q, a protocol for opening authenticated connections, even through NAT. It allows a user to reliably demonstrate their identity (for distributed authentication) and receive real-time data directly from other users, and provides a mechanism for a user to decide whether they want to expose their IP address to a third party before accepting a peer-to-peer connection. It is byte-stream oriented and application-agnostic. Any peer-to-peer application can use Q2Q to open connections and deliver messages.
Twisted Names is both a domain name server as well as a client resolver library. It comes with an "out of the box" nameserver that can read most BIND-syntax zone files as well as a simple Python-based configuration format. It can act as an authoritative server, perform zone transfers from a master to act as a secondary, act as a caching nameserver, or any combination of these. The client resolver library provides functions for querying all commonly used record types as well as a replacement for the blocking gethostbyname() function provided by the Python stdlib socket module.
Twisted Mail provides client and server implementations of SMTP, POP3, and IMAP4. These differentiate themselves from the Python standard library implementations both by presenting a much higher-level, easy-to-use interface and in their server components, which allow the implementation of custom servers for each protocol without dealing with protocol-level issues. Twisted Mail includes a simple demonstration email server which accepts messages over SMTP, stores them in a Maildir arrangement, and can serve them to clients over POP3.
Twisted Words provides implementations of a handful of IM protocols, including IRC, MSNP8, OSCAR, TOC, and Jabber. It also comes with a multi-protocol server built around a few simple interfaces, the goal of which is to facilitate implementations of novel servers, clients, and bots. Out of the box, it comes with server that accepts connections over IRC and PB and seeks out installed third-party plugins to support other interfaces (for example, a Nevow LivePage-based Web interface).
Conch is an SSHv2, Telnet, and VT102 implementation. It interfaces well with other Python projects such as Imagination, and includes an experimental console windowing library (Insults) and support for rudimentary line editing behaviors. A new implementation of Twisted's Manhole application is also included, featuring server-side input history and interactive syntax coloring.