DIVERSITYOFTHEMASHUPECOSYSTEMMichaelWeissandSolangeSariDepartmentofSystemsandComputerEngineering,CarletonUniversity,1125ColonelByDr,Ottawa,Canadaweiss@sce.carleton.ca,ssari@connect.carleton.caKeywords:Mashups,OpenAPIs,Ecosystems,Diversity,Phylogenetictrees,Birth-deathmodels.Abstract:MashupsallowuserstodevelopapplicationsfromavarietyofopenAPIs.Thecreationofmashupsissup-portedbyacomplexecosystemofinterconnecteddataproviders,mashupplatforms,andusers.AsignofahealthyecosystemisthatthenumberanddiversityofAPIsandmashupsintheecosystemincreasescontinu-ously.Inthispaper,wedescribeamodeloftheevolutionofthemashupecosystemthatallowsustoestimatethediversificationofthemashupecosystemovertime.Inthismodelweshowtheevolutionaryrelationshipsbetweenmashupsasbranchesinaphylogenetictree.Wediscusshowthediversificationrateofthemashupecosystemcanbeestimatedbyfittingthistreetoabirth-deathprocessmodel.Theresultsofourresearchshowthatthediversityofthemashupecosystemisincreasingwithtime,however,notmonotonically.1INTRODUCTIONmashupswithonlyoneAPI,suchasFlickrorGoogleMaps.Lateron,APIswerecombined.MashupsthatMashupsallowuserstodevelopapplicationsfromacombinebothAPIsgaveorigintothenewFlickrandvarietyofopenAPIs(Yuetal.,2008).Forexam-GoogleMapsspecies.Thus,GoogleMapsisconsid-ple,theGoogleMapsAPIgeneratesmapsforagiveneredextinctintheFlickrclade,andviceversa.location,anditsoutputcanbecombinedwithotherFromthisperspective,wedefinethediversifica-openAPIsanduser-supplieddata.Thecreationoftionofthemashupecosystemasthecreationofamashupsissupportedbyacomplexecosystemofin-greatervarietyofmashups.Diversificationcanbeterconnecteddataproviders,mashupplatforms,andmodeledasabirthanddeathprocess,fromwhichweusers(withheld).Itisasignofahealthyecosystemcanestimatetherateofdiversificationasthediffer-thatthenumberanddiversityofAPIsandmashupsencebetweenspeciationandextinctionrate.Theevo-intheecosystemincreasescontinuously.Thegrowthlutionofthemashupecosystemcanbereconstructedofthemashupecosystemhasbee