Update History

For the record, in Tables

and

we list the official main versions of JETSET and PYTHIA, respectively, with some brief comments.

**Table:** The main versions of JETSET, with their date of appearance, published manuals, and main changes from previous versions.
No.	Date	Publ.	Main new or improved features
1	Nov 78	[Sjö78]	single-quark jets
2	May 79	[Sjö79]	heavy-flavour jets
3.1	Aug 79	--	2-jets in $\mathrm{e}^+\mathrm{e}^-$ , preliminary 3-jets
3.2	Apr 80	[Sjö80]	3-jets in $\mathrm{e}^+\mathrm{e}^-$ with full matrix elements,
			toponium $\to \mathrm{g}\mathrm{g}\mathrm{g}$ decays
3.3	Aug 80	--	softer fragmentation spectrum
4.1	Apr 81	--	baryon production and diquark fragmentation,
			fourth-generation quarks, larger jet systems
4.2	Nov 81	--	low- $p_{\perp}$ physics
4.3	Mar 82	[Sjö82]	4-jets and QFD structure in $\mathrm{e}^+\mathrm{e}^-$ ,
	Jul 82	[Sjö83]	event-analysis routines
5.1	Apr 83	--	improved string fragmentation scheme, symmetric
			fragmentation, full 2 $^{\mathrm{nd}}$ order QCD for $\mathrm{e}^+\mathrm{e}^-$
5.2	Nov 83	--	momentum-conservation schemes for IF,
			initial-state photon radiation in $\mathrm{e}^+\mathrm{e}^-$
5.3	May 84	--	`popcorn' model for baryon production
6.1	Jan 85	--	common blocks restructured, parton showers
6.2	Oct 85	[Sjö86]	error detection
6.3	Oct 86	[Sjö87]	new parton-shower scheme
7.1	Feb 89	--	new particle codes and common-block structure,
			more mesons, improved decays, vertex information,
			Abelian gluon model, Bose-Einstein effects
7.2	Nov 89	--	interface to new standard common block,
			photon emission in showers
7.3	May 90	[Sjö92d]	expanded support for non-standard particles
7.4	Dec 93	[Sjö94]	updated particle data and defaults

**Table:** The main versions of PYTHIA, with their date of appearance, published manuals, and main changes from previous versions.
No.	Date	Publ.	Main new or improved features
1	Dec 82	[Ben84]	synthesis of predecessors COMPTON, HIGHPT and
			KASSANDRA
2	--
3.1	--
3.2	--
3.3	Feb 84	[Ben84a]	scale-breaking parton distributions
3.4	Sep 84	[Ben85]	more efficient kinematics selection
4.1	Dec 84		initial- and final-state parton showers, $\mathrm{W}$ and $\mathrm{Z}$
4.2	Jun 85		multiple interactions
4.3	Aug 85		$\mathrm{W}\mathrm{W}$ , $\mathrm{W}\mathrm{Z}$ , $\mathrm{Z}\mathrm{Z}$ and $\mathrm{R}$ processes
4.4	Nov 85		$\gamma \mathrm{W}$ , $\gamma \mathrm{Z}$ , $\gamma\gamma$ processes
4.5	Jan 86		$\H ^0$ production, diffractive and elastic events
4.6	May 86		angular correlation in resonance pair decays
4.7	May 86		$\mathrm{Z}'^0$ and $\H ^+$ processes
4.8	Jan 87	[Ben87]	variable impact parameter in multiple interactions
4.9	May 87		$\mathrm{g}\H ^+$ process
5.1	May 87		massive matrix elements for heavy quarks
5.2	Jun 87		intermediate boson scattering
5.3	Oct 89		new particle and subprocess codes, new common-block
			structure, new kinematics selection, some
			lepton-hadron interactions, new subprocesses
5.4	Jun 90		-dependent widths, resonances not on the mass shell,
			new processes, new parton distributions
5.5	Jan 91		improved $\mathrm{e}^+\mathrm{e}^-$ and $\mathrm{e}\mathrm{p}$ , several new processes
5.6	Sep 91	[Sjö92d]	reorganized parton distributions, new processes,
			user-defined external processes
5.7	Dec 93	[Sjö94]	new total cross sections, photoproduction, top decay
6.1	Mar 97	[Sjö01]	merger with JETSET, double precision, supersymmetry,
			technicolor, extra dimensions, etc. new processes,
			improved showers, virtual-photon processes
6.2	Aug 01	[Sjö01a]	Les Houches Accord user processes, -parity violation
6.3	Aug 03	[Sjö03a]	improved multiple interactions, $p_{\perp}$ -ordered showers,
			SUSY Les Houches Accord interface
6.4	Mar 06	this	none so far