# 2. Introduction

## 2.1. What is TortoiseHg?

TortoiseHg is a set of graphical tools and a shell extension for the Mercurial distributed revision control system.

Note

hg is the symbol for the chemical element Mercury

On Windows,
  TortoiseHg consists of the Workbench graphical application, a shell extension which provides overlay icons and context menus in your file explorer, and a command line program named `thg.exe` which can launch the TortoiseHg tools. Binary packages of TortoiseHg for Windows come with Mercurial and a merge tool and are thus completely ready for use “Out of the Box”.
On Linux,
  TortoiseHg consists of a command line thg script and a Nautilus extension which provides overlays and context menus in your file explorer. You must have Mercurial installed separately in order to run TortoiseHg on Linux. TortoiseHg binary packages list Mercurial as a dependency, so it is usually installed for you automatically.

Note

On Windows, TortoiseHg includes both thg.exe and thgw.exe. The latter is intended to be launched from desktop shortcuts or menu entries as it will refuse to open a command console. thg.exe is for use on the console, and can provide command line help. The thg.cmd batch file that our installer adds into your PATH runs thg.exe.

TortoiseHg is primarily written in Python and PyQt (the Windows shell extension being the notable exception). The thg script and TortoiseHg dialogs can be used on any platform that supports PyQt, including Mac OS X.

## 2.2. Installing TortoiseHg

### 2.2.1. On Windows

TortoiseHg comes with an easy to use MSI installer. You can always find the most up to date release on our website. Simply double click on the installer file and follow its instructions.

After a first time install, a re-login is usually required to start the icon overlays.

During upgrades, the installer will ask to close or restart any applications that have loaded the TortoiseHg shell extension. If you allow those applications to be closed, the upgrade will not require a reboot or logout. If other users are logged in, or if there are applications which cannot be shutdown, a reboot will be required to complete the install.

Note

If you have a legacy version of TortoiseHg installed, the installer will require that you to remove it. The uninstall can be initiated from the control panel or the start menu.

Warning

Legacy uninstallers (<=0.9.3) have a tendency to delete your user Mercurial.ini file, so backup your file before uninstalling the older TortoiseHg versions. This is not a problem with the newer MSI packages.

Legacy TortoiseHg installers (prior to version 1.0) were built with InnoSetup. They installed a TortoiseOverlay package as a separate application, so you always saw both TortoiseHg and TortoiseOverlay as two applications in the Add/Remove Programs control panel program. (On x64 platforms, there were two TortoiseOverlays, one for x86 processes and one of x64 processes).

The new MSI installers for TortoiseHg include the TortoiseOverlay packages as “merge modules” so they do not appear as separate applications anymore. It should be safe to uninstall the older TortoiseOverlay applications from Add/Remove Programs after you uninstalled the legacy (<=0.9.3) TortoiseHg installer, unless you have other Tortoise products that still use the separate TortoiseOverlay MSI approach (TortoiseCVS or TortoiseBZR).

Note

TortoiseOverlay is a shim package that allows multiple Tortoise style shell extension clients to share overlay slots. This is necessary because even modern Windows platforms only support a limited number of overlay slots (11-14). TortoiseOverlay packages are created by the TortoiseSVN developers.

To be completely safe, there are two approaches you can take:

1. Just leave the old TortoiseOverlay packages installed. They do not harm anything.
2. Uninstall all the old TortoiseOverlay packages, then re-install all of your Tortoise products until they are all functional.

Finally, if you have problems with the shell extension even after re-logging in, we recommend you re-run the installer and select the Repair option. There were problems with a few versions of TortoiseOverlay that cause upgrades to subtly fail until the Repair process is run.

#### 2.2.1.1. Language settings

The TortoiseHg user interface has been translated into many languages. Language packs are not required since all available languages are installed by default. You can select your preferred UI Language in the global settings tool.

The Windows shell extension context menus get their translations from the Windows registry. Translations for many locales were installed under `C:\Program Files\TortoiseHg\i18n\cmenu`. Select the locale you would like to use, double-click on it, and confirm all requests.

### 2.2.2. On Linux and Mac

The most recent Linux packages can be found on our download page.

For Mac OS X, no packages are available but you can run thg and all the dialogs via the source install method. For details, see Mac OS X.

Note

If you install TortoiseHg from source, you need to add our `contrib/mergetools.rc` file to your HGRC path in some way. One approach is to %include it from your `~/.hgrc file`.