I'm a software practitioner and I'm writing a survey on algebraic structures for personal research and am trying to produce examples of how these structures are used in theoretical computer science (and to a lesser degree, other sub-fields of computer science).
Under group theory I've come across syntactic monoids for formal languages and trace and history monoids for parallel/concurrent computing.
From a ring theory standpoint, I've come across semiring frameworks for graph processing and semiring based parsing.
I have yet to find any uses of algebraic structures from module theory in my research (and would like to).
I'm assuming that there are further examples and that I'm just not looking in the right place to find them.
What are some other examples of algebraic structures from the domains listed above that are commonly found in theoretical computer science (and other sub-fields of computer science)? Alternatively, what journals or other resources can you recommend that might cover these topics?