| BitString_t | A bit string |
| cf_struct | Table of constituents |
| CfInfo | Constituent data structure |
| Entry_t | A group element |
| factor_t | Internal representation of a factor |
| FPoly_t | A Factored Polynomial |
| GreasedMatrix_t | A greased matrix |
| GrExtractionTable_t | Extraction table for greasing |
| IntMatrix_t | An Integer Matrix |
| Lat_Info | Module Structure Information |
| LdLattice_t | Graphical lattice representation |
| LdNode_t | Node in a graphical lattice representation |
| MatRep_t | A matrix representation |
| Matrix_t | A matrix over a finite field |
| MatrixSet_t | A set of matrices |
| MatrixSetElement_t | An element of a matrix set |
| MtxApplication_t | Application data |
| MtxApplicationInfo_t | Application information structure |
| MtxErrorRecord_t | Run-time error information |
| MtxFile_t | MeatAxe data file object |
| MtxFileInfo_t | Source file information |
| nodestruct | A submodule |
| Perm_t | A Permutation |
| Poly_t | A Polynomial |
| Set_t | A Set of Integers |
| SpinUpInfo_t | Spin-up Parameters |
| StfData | Structured text file |
| TkData_t | Tensor condensation state |
| tPivotEntry | Internal data structure |
| WgData_t | Word Generator Data |