Git hosting
Git hosting provides a fast and an extremely resourceful distributed version control system. It is best suited for the collaborative 
development of softwares. Git hosting is mainly associated with the speed factor. It was designed and developed previously by Linus Torvalds for the development of Linux kernel. The Git working directories are not only network access or central server dependent but are also full-fledged repositories with distinct capabilities for a complete revision tracking. Git is a software which comes for free and is distributed under the terms of the GNU General Public License version 2.
The development of Git hosting began after the Linux kernel developers decided to renounce the access to the proprietary BitKeeper system. The BitKeeper system was its actual inspiration. The development of Git commenced on April 3, 2005, the project being announced on April 6 and it was turned into self-hosting on April 7. Git was initially designed as a low level version control system with engine capabilities on which others could write front ends, such as the Cogito or StGIT. But since after that the core Git project has become a complete revision control system and can be used directly.
Characteristic features of Git Hosting:
Git hosting supports a non linear development: Git hosting supports speedy branching and merging, and also includes particular tools for the visualization and navigation of a non linear development history.
Distributed development: Git hosting gives all the developers a local copy of the development history and all the changes that occur are copied from one repository to the other.
It is compatible with the existing systems and protocols: The repositories can be published via the FTP, HTTP, rsync, or a Git protocol over a plain socket or a ssh.
It provides for handling of large projects with ease: Git hosting is very fast and scalable it does not at all get slower as the history of 
the project grows larger.
Authentication of history: The Git history is usually stored in such a way that the name of a particular revision depends upon the full development history which leads up to that commit. Once it has been published, it is not possible to make any kind of changes in the old versions without being noticed.
Design based on Toolkit: Git was designed originally as a set of programs written in C. Even though most of the scripts have been rewritten in C for the sake of speed and portability, the actual design remains the same and it is quite easy to chain the components together.
Git hosting was primarily developed on Linux. But it can be used on other Unix-like operating systems which include Solaris, BSD and Darwin. Git hosting works well on systems based on POSIX such as the Linux system. Git hosting also runs on Microsoft Windows. This has two variants: A native Microsoft Windows port, called Msysgit and Cygwin. Though a bit slower than the Linux version, the Msysgit is considerably fast and can be effectively used in production, with negligible difficulty. The other variant Cygwin, is significantly slower for commands written as shell scripts.
The various other alternatives for Git hosting include: Agit, Eclipse, TortoiseGit, IntelliJ IDEA, KDevelop, NetBeans, Qt Creator, SlickEdit and Xcode 4.
More info:
Official Git homepage
Linus Torvalds speaks about Git (video)