Building in hierarchical support in a flat file format.
GRML is essentially a two-dimensional format. It uses columns as one dimension and results as the other. This is similar to relational databases, such as Microsoft Access or IBM DB2. To add a level of depth to the format, the concept of dimensions was added as a tag keyword. Using this, there is support for data grouping across another dimension. It might be called a third dimension.
Using the dimensional approach necessarily creates roadblocks for representing hierarchical data. XML supports both flat and hierarchical data. It does lack a dimensional element, however. XML does represent data using an object-oriented principles. It is nice, but a file format representing dimensions and hierarchies is ideal. This is a challenging goal for GRML, but it provides benefits, if practical.
Find out more about GRML web browsers.