Sverre Aarseth's research into numerical simulations of manybody (Nbody) gravitational interactions spans over 40 years and is reported in several publications and his book. Sverre has developed a set of FORTRAN codes which describe the dynamics very closely, and these are regarded by many as the de facto standard.
Sverre Aarseth's codes are available freely for download from the NBody directory at ftp://ftp.ast.cam.ac.uk/pub/sverre/. Your browser should present you with an FTP viewer window when you click on this link and you should be able to copy whole code group directories at a time.
Use the links below to identify and download the specific files that you need.
At any time if you would like further information, please contact Sverre Aarseth.
Code Group  Filename  Filesize (Kb)  Notes 

CODES  2  General textual description of the codes.  
nbody1  README  1 
The version nbody1.tar.Z is in full REAL*8. The file nbody1_real4.tar.Z is the old version with mixed REAL*4/*8 precision which is kept for historical reasons. The recent file nbody1h.tar.gz is the Hermite blockstep formulation for workstations and (micro)GRAPE, developed with Jun Makino in 1991. 
nbody1.tar.Z  26  
nbody1_real4.tar.Z  26  
nbody1h.tar.gz  140  
nbody2  nbody2.tar.Z  213 
Directory nbody2 contains the code NBODY2 and an article describing it. The whole file is called nbody2.tar.Z. Inside is the code, the article chap9.tex and also chap9.ps. The article may be produced in TeX using the enclosed macro svnyp.sty (or see New Ast. 6, 277). The code NBODY2H is the Hermite blockstep version of NBODY2. 
nbody2h.tar.Z  185  
nbody3  nbody3.tar.Z  204  One force polynomial with full regularization. 
nbody4  README  1 
The public GRAPE6 or microGrape code NBODY4 and the equivalent brute force code for workstations or laptops called BRUT4. The current versions were updated 12 March 2006. Introduction to running simulations. 
nbody4.tar.gz  360  
brut4.tar.gz  340  
intro_nbody4.pdf  1  
nbody5  README  1 
The code NBODY5 has been heavily used but is no longer updated. NBODY6 is recommended instead. 
nbody5.tar.Z  289  
nbody6  README  1 
README contains some past history of NBODY6. Tar file for the GPU directory and library. pdf file of new NBODY6GPU paper.

nbody6.tar.gz  980  
old6.tar.gz  640  
man6.pdf  200  
old6.ps  306  
intro_nbody6.pdf  1  
README2  1  
guide.pdf  30  
gpu.tar.gz  65  
gpu2.tar.gz  95  
nbody6gpu.pdf  95  
planet  planet.tar.Z  16 
PLANET is a Hermite code for planetesimals. PLANET3 is a planetary code with fragmentation. 
planet3.tar.Z  30  
triple  triple.tar.Z  13 
Basic version of threebody regularization. TRIPLE movie code with X11 graphics. 
movie3.tar.Z  26  
chain  chain.tar.Z  20 
Basic chain version. CHAIN2 includes the slowdown procedure (Cel. Mech. 64, 197). Other versions are available upon request. movie.tar.Z holds X11 movie version of CHAIN. 
chain2.tar.Z  26  
movie.tar.Z  48  
comove  comove.tar.Z  28  Cosmological Nbody code in comoving coordinates. 
errata  README  1 
The file "errata" is a text file for book errata of 3/10/03 and "errata.ps" is the corresponding postscript file. The text file "errata2" contains subsequent mistakes. 
errata  2  
errata.ps  54  
errata2  1  
hermit  hermit.tar.Z  16 
HERMIT is a basic Hermite Nbody code. HERMIT2 uses timesymmetric Hermite method of Kokubo et al. HERMIT4 is timesymmetric Hermite with BurdetHeggie regularization. The manual is described in the postscript file hermit4.ps. 
hermit2.tar.Z  16  
hermit4.tar.Z  43  
hermit4.ps  133  
toy  README  15 
Toy codes for unperturbed twobody motion. Five different regularization methods are implemented. A new version called hermit.tar.Z includes PostNewtonian perturbations derived from the 2005 paper of Mora and Will. 
toy.tar.Z  65  
hermit.tar.Z  22  
multireg  README  1  
triple.tar.Z  22 
triple.tar.Z holds the threebody regularization code described in the manual. 

chain0.tar.Z  14  
chain.tar.Z  45  
manreg.ps  220  
triple2.tar.Z  32  
triple3.tar.Z  50  
kozai.tar.Z  30  
talks  talks.tar.gz  600  Nbody talks Nov 2006. 
nbody0  nbody0.f  1  Compact fourthorder Hermite blockstep code. 