  lenstronomy is an Astropy-affiliated Python package for gravitational lensing
simulations and analyses. lenstronomy was introduced by Birrer and Amara (2018)
and is based on the linear basis set approach by Birrer et a. (2015). The user
and developer base of lenstronomy has substantially grown since then, and the
software has become an integral part of a wide range of recent analyses, such
as measuring the Hubble constant with time-delay strong lensing or constraining
the nature of dark matter from resolved and unresolved small scale lensing
distortion statistics. The modular design has allowed the community to
incorporate innovative new methods, as well as to develop enhanced software and
wrappers with more specific aims on top of the lenstronomy API. Through
community engagement and involvement, lenstronomy has become a foundation of an
ecosystem of affiliated packages extending the original scope of the software
and proving its robustness and applicability at the forefront of the strong
gravitational lensing community in an open source and reproducible manner.
