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Sledge BETA

A free and open source alternative to Valve's Hammer Editor for Half-Life 1.

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Sledge is no longer being actively developed.


The Sledge Editor currently only works on Goldsource - that is, the Half-Life 1 engine from 1998. It does not work on HL2, CSGO, Gmod, or any other Source-based game.

Beta Build!

Sledge is currently in public beta, which means that there are still many changes being made and it will be updated often. Beta builds may be unstable.

What is Sledge?

Sledge is a completely free and open-source replacement for Valve's Hammer Editor, with a focus on compatibility with the Goldsource engine. The purpose of Sledge is to offer advanced editing features from later versions of Hammer and other editors and make them available to all users, regardless of which engine they choose to use.

Sledge uses the same file formats as Hammer does (RMF, MAP, VMF) and maps are compatible between both programs. The editing process is almost identical to Hammer, the hotkeys are the same, as well as many of the screen elements and dialogs. Switching to Sledge will not be difficult for users who are familiar with Hammer.

Sledge Main Window

Sledge Requirements

  • Windows 7 or higher
  • Microsoft .NET 4.7.2 or higher (Download Here)
  • DirectX 10 compatible graphics card
  • FGD for the game of your choice

Note that WINE/Mono for Linux and Mac is not supported.

Create Brush Preview

Model Rendering

Advantages of Sledge

  • Sledge brings many editing features available in Hammer 4 into the Goldsource editing environment.
  • It is built using modern frameworks and libraries, and is tested on modern operating systems.
  • It is constantly being enhanced and new features are always being added.
  • It is open source, which means the source code is available to everybody to modify and improve.

Features in Sledge

  • Runs on modern operating systems and graphics cards
  • Can take advantage of multiple monitors
  • Full support for Goldsource editing
  • Reads and writes RMF, MAP, VMF files
  • Complete compatibility with Hammer maps
  • Proper decimal precision for sub-grid geometry
  • Support for large maps
  • Support for multiple visgroups per object
  • Automatic visgrouping
  • Improved texture browser filtering and display options
  • A huge number of settings to customise to your liking
  • ...and much more!

Texture Browser

Extremely Customisable

Don't like the colour of the grid lines? Prefer your background colours to be blue? Want to automatically switch to the selection tool after you create a brush? How about changing the hotkeys? Sledge has you covered for all this and more!

Texture Browser

Sledge Public Beta

Sledge is currently in beta stage, so it may be unstable and some features are missing. Missing features include:

  • Model loading
  • Cordon clipping during compile
  • Built-in support for prefabs/instances
  • Automatic detection of game configurations

Source Support

The current milestone is to fully support Goldsource editing. Once HL1 editing is stable, work to add support for Source will begin. Sledge does not support Source currently.

Future Possibilities

Because Sledge is open source, the possibilities for future expansion are endless. Some popular ideas include the following:

  • Collaborative editing and multi-user support
  • A plugin system and support for scripting
  • Built-in support for version control systems like SVN and Git
  • Powerful displacement editing tools
  • A complete 'Sledge SDK' containing other editing and creation tools based on the Sledge code base
  • ...and anything else you can think of!