LIL File Actions, or just lilfa, is a tool to provide a simple GUI for running a command inside a folder that contains a series of files. When lilfa runs it checks the current folder and its parents for a LIL script named fileacts.lil and runs it to populate a list of files using the instructions in the script (alternatively lilfa can run the script passed to it as the first parameter, but the main use case is having it find the script automatically).
The primary idea behind this tool is for it to be called from a file manager (or a command-line shell that supports keybindings) via a toolbar icon, menu command or shortcut key under the currently shown folder/directory and then present the user with a list of files that were collected using the script inside that directory. Then the user will select one (or more, if multiple selection is enabled) file and by pressing the Run button (or Enter key or double clicking the file), some command will be executed inside the directory.
Examples for that would be running a custom map in a game where all maps are separate files under a subdirectory, processing specific source files, booting an emulator or VM using a disk image where all disk images are stored under a directory, running a version control UI where all repositories are inside a directory (e.g. a Fossil repository is a single file and if you put all of your repositories in a single directory then you can use a lilfa script to launch the web UI for any of them), etc.
For examples check the documentation. Also check some additional usage tips, including integration with some file managers.
LIL File Actions is open source under the zlib license, but keep this note in mind.