The crossfire server is the heart of the game. Crossfire is designed around a central server with each client being able to log in and separately interact with the crossfire world.
Servers can be classified by the type of source code they run:

• tag - these servers are running a stable release of crossfire
• trunk - these servers are running the latest development release of crossfire
• branch - these servers are running a non-standard version of crossfire

Server hosts may also choose to modify certain aspects of the game to suit their preference.

• Experience curve - A popular modification is to the experience curve and experience loss upon death to make a particular server more or less challenging.
• tickrate - Currently by default all servers run a tickrate of 120ms between ticks, or, 8.33 ticks per second. The tickrate is used to determine many in game properties like the time, movement and attack speed, grace and sp regeneration and food consumption.
• Maps - Maps may be added or removed from particular servers to improve the in game experience.

• Servers - Information about advertised servers
• Hosting - Guide to hosting your own server

• Linux Server Install Guide - Guide to installing a crossfire server on a linux platform
• Window's Binary Server Install Guide - A guide to installing a crossfire server on Windows platform
• OSX Server Install Guide - A guide to installing a crossfire server on an OSX platform
• BSD - Information on installing servers on BSD
• Solaris - Information on installing servers on solaris

• Crossfire Server Compile Guide

Problem: The server frequently reports “skipping time”

By default, the in-game clock “ticks” about 8 times a second. If the server takes longer than 1/8th of a second to process a tick, the server will skip the next tick and report “skipping time”. Most of the time, this is due to slow disk I/O. Consider mounting /tmp on an in-memory filesystem (such as tmpfs) to improve the I/O performance of map swapping.