OpenTissue has as of February 2018 been relocated to Github. This have been on the agenda for some time, but was greatly promoted by the disappearance of the image server that hosted the project for many years. OpenTissue is a collection of generic algorithms and data structures for rapid development of interactive modeling and simulation. It is the open source library that accompanies the textbook “Physics-based Animation”. The library was created around 2001 by the help and support of a vast number of projects and master thesis students at department of computer science; too many to mention all here. After a decade or so the library grew quite large. It evolved into a pretty high-quality code base. The library has over time influenced many other code bases around the world and is still quite advanced in terms of applying generic programming in C++. The library contains numerical methods for simulating fluids, deformable and rigid bodies as well as many methods for collision detection. Due to lack of resources we no longer provide active support for OpenTissue, but we do maintain a repository for others. The code is provided as it is. No guarantees are given. Use it at your own risk.