Hammer++ vs J.A.C.K.
Hammer++
ficool2.github.ioJ.A.C.K.
jack.hlfx.ruSide by side
| Figure | Hammer++ | J.A.C.K. |
|---|---|---|
| Price from | Free | — |
| Free plan | Yes | — |
| Free trial | — | — |
| Open source | — | — |
| Windows | Yes | Yes |
| macOS | — | Yes |
| Linux | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Game Level Editors | 8.5 (#5) | 7.6 (#14) |
| Editing tools | It adds a 3D gizmo, adjustable pivot, polygon and sprinkle tools, real-time vertex editing, three-point clipping, brush merging and surface movement tools. | Features include curved surfaces, triangulation, UV-Lock, multiple VisGroups, and automatic selection in 3D views. |
| Purpose | Hammer++ is a free modification of Valve’s Hammer editor for the Source engine, intended to be more stable and up to date, with bug fixes and improvements. | J.A.C.K. is a level editor for games using Quake-style BSP architecture. |
| Support | The maker directs users to the official Discord to discuss Hammer++. | Users can submit error reports and feature requests through the project forums; the software is provided without warranty. |
Plans
In their own words
Hammer++
Hammer++ is a free Windows modification of Valve’s Hammer editor for creating maps in the Source engine. It aims to improve stability and keep the editor current through fixes and changes. It can simulate Source lighting inside the editor, with adjustable quality and speed and dynamic updates, and preview particles, fog, skyboxes, rope physics, render effects, and material proxies. Mapping tools include a 3D gizmo, polygon and sprinkle tools, multiple cordons, brush merging, and object placement on floors or ceilings. If the editor crashes, it shows a detailed error message and autosaves open VMF files. Saved VMFs retain precise vertex data while also storing less precise data for compilers and compatibility with other Hammer versions. Downloads bundle HLMV++, which can be installed optionally. The download page lists build 8871, last updated April 14, 2026. The maker directs users to its official Discord for discussion and says the project is not affiliated with Valve. It also notes antivirus software sometimes flags downloads and advises allowing them or adding an exception. The old Source 2013 Multiplayer version is unsupported, and CS:GO support is frozen on build 8864.