Text Mod Management With OpenBLCMM

OpenBLCMM is a community-managed 100% opensource fork of the original BLCMM app, and fixes up a few of the longstanding issues w/ BLCMM. As with the original, OpenBLCMM is a tool for managing text-based mods in BL2, TPS, and the standalone AoDK. Many thanks to LightChaosman for opensourcing the BLCMM core last year, and for everyone who’s helped test and debug OpenBLCMM during its development!

Some notable changes:

  1. It’s 100% open-source
  2. The Windows version is entirely contained in an EXE. No Java install is required! There’s also an installer which will get OpenBLCMM into your Start Menu.
  3. “Pure Java” versions support all current Java versions, up through Java 20
  4. Support for Assault on Dragon Keep (including OE data!)
  5. Object Explorer datapack handling is significantly different, and OE features various speedups and some streamlining.


If you run into problems, feel free to ask questions in the community mod support Discord. Bug reports and feature requests can be submitted at the project Github. Enjoy!

More Detailed Changes

The day-to-day use of OpenBLCMM hasn’t really changed much from the original BLCMM, but there are a few things which are worth noting. I’ll break them out in three sections: one for installation details, another for app changes for all users, and another for modders.


The main change here is that Windows users should have an easier time. OpenBLCMM is compiled up into an EXE, so Windows users no longer have to have Java installed to run the app. Additionally, the recommended way to install is via the new installer. Give it a run, click through some hopefully-familiar-looking dialogs, and you’ll end up with an OpenBLCMM entry in your Start Menu, and also on your Desktop if you chose that option.

There’s also a zipfile of the EXE release, in case you don’t want to use the installer for whatever reason. Keep in mind that the zipfile EXE requires you to have the MS Visual C++ Runtime installed. That’s commonly installed by other programs, so you probably already have it, and the Installer package will install it automatically if need be. if you try to run the EXE and have errors about not finding VCRUNTIME140.dll, though, that’s the package you’ll need to install.

Users on other platforms have archives available which require you to already have Java installed, as you’re probably already used to. We recommend installing Adoptium Temurin for Java. OpenBLCMM currently supports Java 8, 11, 17, and 20.

Changes For All Users

The first thing you might notice is there’s no longer a launcher for OpenBLCMM – you’re sent directly into the app. One side-effect of this is that OpenBLCMM doesn’t do any auto-updates. When new versions are available, the app will let you know in the status area at the bottom, but you’ll have to download and install the updates yourself, if you want. You can turn off the new-version checking from the settings.

You may notice that various things have actually been removed from OpenBLCMM, such as the game launch button, Hex Multitool integration, the old “plugins” system, etc. One of OpenBLCMM’s goals was simplifying its operation a bit, and many of those features were complicating the codebase and causing maintainability problems.

The other main thing that users may notice is that the “Setup game files for mods” dialog now redirects you to PythonSDK instead of offering the hex edits. Installing PythonSDK has been the recommended method of enabling the in-game console and supporting text mods for some time now, and direct hex editing for BL2/TPS/AoDK isn’t actually required. The hex edits are still available via a new “Legacy Hex Edits” dialog if you want, but we strongly recommend just installing PythonSDK instead.

Changes for Modders

The biggest change for modders is that the Object Explorer datapack handling is totally different. Originally, BLCMM would download those from the launcher, based on some settings in the main app. In OpenBLCMM, though, you download them separately and place them in the same directory where your OpenBLCMM.exe/OpenBLCMM.jar lives. Then when the app starts up the next time, it’ll see the data, do a little bit of processing, and they’ll be good to go. The datapacks are also no longer split up by category. Instead, each datapack contains all the available data for the game. This includes classes which have historically been left out of the BLCMM dataset. OpenBLCMM also has support for the standalone Assault on Dragon Keep, and there’s a datapack available for that game. You can see info about which datapacks OpenBLCMM has loaded from the Help -> About menu.

Object Explorer itself had its whole datalib backend rewritten for OpenBLCMM, and there’s been some streamlining and performance improvements as a result. The Class Browser and Object Browser can be used without restriction, instead of having to worry about classes with a lot of objects. There’s a dropdown for the active game inside OE itself, instead of using the dropdown from the main OpenBLCMM window. If you type in a search term which isn’t an object name, OpenBLCMM will immediately switch to fulltext searching mode, rather than popping up a dialog to let you know. There’s been a lot of other little tweaks, which should hopefully be welcome to modders.

Finally, there is still a tab in the settings menu to choose data categories, but those checkboxes only apply to fulltext searches and “refs” searches. The more categories you have selected, the slower those two operations will be, just like with the original BLCMM. Unlike the original, you can change those settings without having to restart the app. So you can feel free to change those whenever you like. As before, including the StaticMesh category will end up noticeably slowing down your searches. There’s also a new “Others” category which includes all the classes which were historically absent from the BLCMM data set.

That’s It!

If you have any bug reports or feature requests, feel free to submit them at the Github page, or ask in the community mod support Discord. You can also check out the Github if you’re interested in helping out with the project, or if you were just curious and wanted to check out the sourcecode.

Happy modding!