The Krylov approximation method provides an efficient approach to perform time-evolutions of quantum states for systems with large-dimensional Hilbert spaces.
When you'll open source, it will be advisable to have a license. There are guides on the subject. As a reference, QuTiP and parts of the scientific/numerical Python ecosystem uses BSD new v 3.0. Other projects in quantum such as Qiskit and Cirq use Apache 2.0. You can add the license by adding from the browser interface of Github a file named LICENSE.txt and it should give you already the templates to choose from.