Approvedby
FirstReader ________________________________________________________
WayneSnyder,Ph.D.
ProfessorofComputerScience
BostonUniversity
SecondReader ________________________________________________________
DavidBarnard,Ph.D.
ProfessorofComputerScience
UniversityofRegina
ThirdReader ________________________________________________________
PaulDourish,Ph.D.
Researcher
XeroxPaloAltoResearchCenter

iv
ACKNOWLEDGEMENTS
Theconventionforacknowledgementsseemstoputprofessionalthanksfirst,andper-
sonaloneslast,butIhavedecidedtoreversethat.Iwanttothankmyfamilyfirst.
Throughout,mywifeEllihashelpedme,madetimeformyworkatthecostofherownease,
andbelievedintheprojectandlifeaftergraduateschool.Despinahasprovidedreliefand
joyandputupwithafatherbusierthanshedeserves.Myparentshavehadencouragedme,
advisedme,andsharedencouragingstoriesabouttheirowndissertationexperiences,invery
differentdisciplines.MybrotherJohnhasencouragedmethroughoutandoftenremindsme
thatpeopleoutsidetheacademyareinterestedinthisstuffaswell.
Manypeoplehavegivenideasorenduredmylongramblingsoneditingandhypertext.I’d
liketothankSteveDeRose,AllenRenear,ElliMylonas,JeremyBornstein,andtherestofthe
CHUGgangforstartingmebackdowntheroadoftextandhypertext.Stevegavemea
wealthofdetailedfeedbackonthedissertationwhenIreallyneededit,remindingmeof
whyI’msointerestedincollaborativeauthorshipanyway:I’vehadgoodmanycollaborators
overtheyears,particularlyhim.WilliamAegerterstartedmethinkingoffreelycombinable
editingoperationsattheHypertextworkshopin1987,eventuallysendingmedownthis
path.FabioVitalihasengagedmeinmanyproductiveandenjoyableargumentsoverthe
years,often(orusually)disagreeingwithme,butalwaysprovidingvaluableperspectives,
enthusiasm,andambition.The“hypertextversioninggroup”comprisingJimWhitehead,
AnjaHaake,DavidHicksandFabioalltalkedversioningandchangecontrolwithmemany
times.
IwrotethefirstPalimpsestpaperinAbdelsalamHeddaya’ssystemsseminar,andhe
helpedmepindownmanydetailsofmyearlierformulations.DavidBarnardhascome
throughwithencouragement,closereadingsofdrafts,andadvice.HeunderstoodPalimpsest
thefastestofthemanypeopletowhomIhaveexplainedit.WayneSnyderandIworkedon