The MMT Language and System

MMT Archives

MMT archives correspond to software projects and are used by MMT to provide project-oriented work flows for any language defined in MMT. They are the primary means to maintain and distribute MMT content.

A number of MMT archives are described in the OAF section.

Writing Archives

Archives can be written in any syntax that MMT can understand natively or for which an importer is registered. The MMT IDE based on jEdit can be used well to write archives in MMT’s native text syntax. The MMT build tool can be used to build MMT archives. This is necessary to make the content available to other MMT applications.

Archives should contain a folder called source, which contains all human-written files. The following folders of an archive have a special meaning to MMT:

Folder Content
source the primary content of the archive in some format that MMT understands natively
content index of all modules (created by MMT when building the archive)
narration index of all documents (created by MMT when building the archive)
relational the relational index with respect to the MMT ontology (created by MMT when building the archive)
export location for the results of exporters that produce auxiliary data from MMT content (created by MMT when running an exporter)
errors holds error and log messages from running build targets (created by MMT when running any build targets)


MMT uses a META-INF directory containing a MANIFEST.MF file.MMT archives are inspired by Java jar archives (which are directory trees zipped into jar files), from where the file name and location is taken. It corresponds to the project definition or project settings file in software projects. Directories containing such a file with a key id are recognized as archives by MMT.

The manifest contains a list of key-value pairs. The syntax is one <key> : <value> instance per line. Archive and application developers are free to introduce keys as they see fit as long as the key contains a . character. (It is recommended to use URIs, e.g., org.mytool.mykey for user-defined keys. The following keys are predefined by MMT:

Key(s) Meaning
id unique identifier of the archive, used to refer to the archive in shell commands
content-base the default namespace in place when entering a source file; this only affects the MMT URIs of the modules in these source files
narration-base the URI prefix prepended to the file paths inside the archives to form document URIs
source, content, narration, relational custom folder names for specific dimensions (see the build tool for details)
ns the default namespace of the archive used for all files that do not declare a namespace
ns-PREFIX a namespace binding for PREFIX that is in effect for all files in the archives (unless a file redefines the prefix)
foundation the (assumed to be common) meta theory for all modules in the archive.