Bible OL is based on Emdros, a database engine for handling analyzed or annotated text. Emdros was developed by Ulrik Sandborg-Petersen of Aalborg University.

An important part of Emdros is an advanced query language, MQL, which makes it possible to search a text for specific constructs. MQL queries can be quite simple, such as “find all verbs in the past tense”, or very complex, such as ”find all sentences containing a singular pronoun, followed by at most three words, followed by a verb in the present tense, except cases where the verb is derived from to be”.

Most people using Bible OL need never learn MQL. If you are interested, you may read more in the Emdros MQL Query Guide.