NEMO - [open source - Unix] An extendible stellar dynamics toolbox; has various programs to create, integrate, analyze and visualize N-body and SPH-like systems. In addition there are various tools to operate on images, tables and orbits, including FITS files to export/import to/from other astronomical data reduction packages. Barnes & Hut Treecode Algorithm - [open source - multiplatform] A guide to a tree code algorithm implementation, used for astronomical N-body simulations. ORSA - Orbit Reconstruction, Simulation and Analysis - ORSA is a C++ framework for the development of algorithms and programs oriented to the simulation and analysis of the orbital evolution of bodies in space. Stellar Astrophysics Software - [open source - Windows] Various programs for stellar astrophysics. Includes CHANDRA stellar structure software for collapsed objects including rotating white dwarfs and neutron stars, and STARCAL for nuclear astrophysics and the stellar structure of main sequence stars with supernova forecasting. The Art of Computational Science - An online `socratic book' pedagogically describing the building of a N-body simulation code for stellar systems. Software (in Ruby) is included. Gadget-2 - The Gadget-2 code is an SPH simulation code designed for cosmological simulations but can be used for a wide variety of astrophysical hydrodynamics simulations with self-gravity. A TIPSY file viewer with MPI capabilities - [Open source - Linux] "Hubble in a bottle!" is visualization software for N-body simulations, which can be run in parallel using MPI for visualizing very large simulation results. Simulation output must be in TIPSY format. Cloudy & Associates - Cloudy is an extensive, well-established, large-scale spectral synthesis code designed to simulate fully physical conditions within an astronomical plasma and then predict the emitted spectrum. The web page contains links to papers published with cloudy, the most recent version of the software itself, and a discussion board. COSMOMC-- Monte Carlo evaluation of CMB parameters - COSMOMC calculates a fast Markov Chain Monte-Carlo exploration of cosmological parameter space for an input set of constraints. FLASH -- AMR reacting hydrodynamics - The FLASH code is a reacting hydrodynamics code with adaptive mesh refinement for general astrophysical hydrodynamics problems. DUSTY -- Radiation transfer through dust - DUSTY calculates the emerging spectrum of radiation from some source viewed after processing by a dusty region. The original radiation is scattered, absorbed and reemitted by the dust, and the emerging processed spectrum often provides the only available information about the embedded object. DUSTY can handle both planar and centrally-heated spherical density distributions. The number of independent input model parameters is minimized by fully implementing the scaling properties of the radiative transfer problem, and the spatial temperature profile is found from radiative equilibrium at every point in the dusty region. DUSTY has built in optical properties for the most common types of astronomical dust and comes with a library for many other grains. Grav-Sim - Grav-Sim is for astronomy and physics enthusiasts to conduct gravity simulations at home. It models a set of bodies gravitating under Newton's laws of motion. Radex - A free computer program to calculate the strengths of atomic and molecular lines from interstellar clouds which are assumed to be homogeneous. Includes installation and running instructions and explains the output.