Tor: Documentation

Running Tor

The Tor Technical FAQ Wiki should be the first place you look. The Guide to Torifying various applications is also popular. (While we monitor the Wiki page to help ensure accuracy, the Tor developers are not responsible for the content.)
The Abuse FAQ is a collection of common questions and issues discussed when running a Tor relay.
The Tor Legal FAQ is written by EFF lawyers. It aims to give you an overview of some of the legal issues that arise from the Tor project in the US.
The manual lists all the possible entries you can put in your torrc file. We also provide a manual for the development version of Tor.
The Tor wiki provides a plethora of helpful contributions from Tor users. Check it out!
The Tor IRC channel (for users, relay operators, and developers) is #tor on irc.oftc.net.
We have a bugtracker. If you have a bug, especially a crash bug, read how to report a Tor bug first and then tell us as much information about it as you can in the bugtracker. (If your bug is with Privoxy, your browser, or some other application, please don't put it in our bugtracker.)
Try the or-talk mailing list below.
As a last resort, look through the Tor contact page.

The or-announce mailing list is a low volume list for announcements of new releases and critical security updates. Everybody should be on this list. There is also an RSS feed of or-announce at gmane.org.
The or-talk list is where a lot of discussion happens, and is where we send notifications of prerelease versions and release candidates.
The or-dev list is for posting by developers only, and is very low traffic.
A list for cvs commits may be interesting for developers.

The design document (published at Usenix Security 2004) gives our justifications and security analysis for the Tor design: PDF and HTML versions available.
Our follow-up paper on challenges in low-latency anonymity (still in draft form) details more recent experiences and directions: PDF draft.
Our paper at WEIS 2006 — Anonymity Loves Company: Usability and the Network Effect — explains why usability in anonymity systems matters for their security: PDF.
Our preliminary design to make it harder for large firewalls to prevent access to the Tor network is described in design of a blocking-resistant anonymity system: PDF draft and HTML draft. You can also see slides and video from Roger's 23C3 talk. Want to help us build it?
The specifications aim to give developers enough information to build a compatible version of Tor:
- Main Tor specification
- Tor version 3 directory server specification (and older version 1 and version 2 directory specifications)
- Tor control protocol specification
- Tor rendezvous specification
- Tor path selection specification
- Special hostnames in Tor
- Tor's SOCKS support and extensions
- How Tor version numbers work
- In-progress drafts of new specifications and proposed changes
Look at the slides (PDF) and video (torrent) from the Tor talk Roger gave at What the Hack (WTH). We also have slides and video of the WTH talk on hidden services.

The Tor wiki provides a plethora of helpful contributions from Tor users. Check it out!
The hidden wiki is a portal for all things about hidden services.
A list of supporting programs you might want to use in association with Tor.
Weasel's graph of the number of Tor relays over time.
The Tor detector or the other Tor detector try to guess if you're using Tor or not.
Check out Geoff Goodell's Tor Network Status page, the Tor Status page, the other Tor Status page, or Xenobite's Tor node status page. Remember that these lists may not be as accurate as what your Tor client uses, because your client fetches all the authoritative directories and combines them locally.
Read these papers (especially the ones in boxes) to get up to speed on the field of anonymous communication systems.

Browse the Tor source repository: (which may not necessarily work or even compile)