Source Level Editor (SLE)
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Source Level Editor (SLE)
Developer(s)
Cvoxalury
Initial release
Ocotober 09, 2025
(2.104)
(2.104)
Stable release
Actively updated
Operating system
Type
Map Editor
Distribution
Freeware
Website
Download
Version
2.104
Source Level Editor (SLE) is a custom edited version of 
Hammer 4.x. It is not meant to be a radical overhaul. Rather, it iterates and adds polish to the basic workflow to make mapping experience smoother, more consistent, expanded, and in some areas: automated.
Development of SLE started in November 10, 2020 by Cvoxalury.
Features
Tool improvements:
- All Block Tool primities are previewed before creation, including preview of arches and toruses.
- 3-Point clipping is added, allowing for freeform clipping at any angle.
- Face Edit Tool supports growing selection by angle and texture skewing (a.k.a. shearing).
- Displacement Tool supports free dragging of vertices, 45° angle XY sculpting axis, fixed Face Normal axis.
- Vertex Edit Tool supports XYZ transform for vertices and collapsing edges with the Delete key.
- Material Browser includes Favourites materials list specified per-game.
- Sound Browser now supports parsing soundscapes for selecting them.
- Model Browser now displays attachments and can filter out Only Used models.
Render improvements:
- SLE can display both regular skybox and 3D Skybox.
- Material Proxies work in 3D View.
- Several visual entities have previews, such as beams and spotlights.
- Rendering of Tool Textures and Editor Objects is toggleable.
UI improvements:
- Hotkeys are now defined in an external, user-editable file and can be reassigned for every supported command.
- Customisable 2D and 3D colours (such as grid lines, the void, selected objects, instances) can be configured in the Options.
- Run Map Dialogue (non-Expert) has been expanded with common compile options.
- Numerous tool and config dialogues have been cleaned up and/or expanded.
Stability improvements:
- Multiple crash bugs, performance slowdowns and limits from the original Hammer have been dealt with.
Supported and Unsupported games
Fully supported games are:
- Half-Life 2 and its Episodes
- Half-Life 2: Deathmatch
- Portal
- Team Fortress 2
- Day of Defeat: Source
- Counter-Strike: Source
- Source SDK Base 2013 based games and mods
Unsupported games ( untested / very limited support / or lack of any support ) include:
- Games on older Source branches (sdk 2007 etc)
- Garry's Mod
- Alien Swarm
- Left 4 Dead 1 / 2
- Portal 2
- CS:GO and newer games.