- No external dependencies (no BLAS or any other C/Fortran library needed). Just plain Common Lisp;
- Represents mappings from one dimension onto another using any scheme you want (there are two built-in schemes, hash and compressed-vector, but you can roll your own and plug it);
- Flexible: works with any data type;
- Heavily optimized: traversing the tensor can be extremely fast (in one specific situation, it was 10 times faster than a naive implementation in C++);
- Somewhat portable: works with SBCL, ABCL, CCL aka Clozure Common Lisp, CMUCL, Clisp, ECL, GCL, XCL, LispWorks, and Allegro Common Lisp. Probably works also with other Lisps also (not fully tested);
- ASDF installable;
- Easy to use, with introductory documentation (not only on-line);
- Comes with description of the internals of the library.
The package is asdf-installable.