Hi Cafe, I’m glad to announce a new release of my simulation library Aivika written in Haskell. It is focused on DES and System Dynamics. I strongly recommend to upgrade to this version for everyone who uses my library. It contains an important fix in that how the TimingStats statistics is gathered. A more simple SamplingStats is usually used. But in the recent versions I started using more widely TimingStats too. This is a kind of (immutable) statistics which is bound up to the simulation time. For example, the queue size statistics is collected as TimingStats, while other queue properties are usually collected as SamplingStats. The SamplingStats is used to be working. But I felt that there was something wrong with TimingStats. Now TimingStats is finally fixed. As a consequence, the queueRate function gives us a result, which suits very well to Little’s rule with good precision in the examples included in the distributive. So, please upgrade to a new version of Aivika (and related libraries) as possible. Besides, I added debugging facilities to the library. These are functions traceEvent, traceProcess, traceStream and so on. They allow tracing the behavior of the simulation model in time. Finally, the Aivika simulation library can be definitely translated to JavaScript with help of the Haste compiler and it works fine! Only I had to use random numbers different from that one, which is specified with help of the SimpleGenerator data constructor. Please read the notes [2] on the wiki page of my project on GitHub. Thanks, David [1] http://hackage.haskell.org/package/aivika http://hackage.haskell.org/package/aivika [2] https://github.com/dsorokin/aivika/wiki/Compiling-to-JavaScript