Theadventofmulticoreprocessorshasrenewedinterestintheideaofincorporatingtransactionsintotheprogrammingmodelusedtowriteparallelprograms.Thisapproach,knownastransactionalmemory,offersanalternative,andhopefullybetter,waytocoordinateconcurrentthreads.TheACI(atomicity,consistency,isolation)propertiesoftransactionsprovideafoundationtoensurethatcon-currentreadsandwritesofshareddatadonotproduceinconsistentorincorrectresults.Atahigherlevel,acomputationwrappedinatransactionexecutesatomically-eitheritcompletessuccessfullyandcommitsitsresultinitsentiretyoritaborts.Inaddition,isolationensuresthetransactionpro-ducesthesameresultasifnoothertransactionswereexecutingconcurrently.Althoughtransactionsarenotaparallelprogrammingpanacea,theyshiftmuchoftheburdenofsynchronizingandco-ordinatingparallelcomputationsfromaprogrammertoacompiler,toalanguageruntimesystem,ortohardware.Thechallengeforthesystemimplementersistobuildanefficienttransactionalmemoryinfrastructure.Thisbookpresentsanoverviewofthestateoftheartinthedesignandimplementationoftransactionalmemorysystems,asofearlyspring2010.