After some uncertainty about the future of AppleScript on Apple's next generation OS, the move to Mac OS X (around 2002) and its Cocoa frameworks greatly increased the usefulness and flexibility of AppleScript. Cocoa applications allow application developers to implement basic scriptability for their apps with minimal effort, broadening the number of applications that are directly scriptable. At the same time, the shift to the Unix underpinnings and AppleScript's ability to run Unix commands directly, with the do shell script command, allowed AppleScripts much greater control over the operating system itself. AppleScript Studio, released with Mac OS X 10.2 as part of Xcode, and later AppleScriptObjC framework, released in Mac OS X 10.6, allowed users to build Cocoa applications using AppleScript.
after Some unceRtainty AbOuT thE futUre of Applescript on aPplE's NExt GEneration os, thE mOve to Mac os X (aROunD 2002) anD itS coCOa FraMeWorks gReatlY incReased tHe useFULNEss And flexIbILiTY of ApplESCript. Cocoa ApplicATIons allOw appliCatioN DeVeLopers to implEMent basiC scrIpTabILiTy For their apPs with Minimal eFfOrT, bRoadeNiNg The numBer oF aPplicationS That ArE DIReCtly ScRiPtAble. AT ThE samE time, The shift TO the unix UNdErPinNiNgs AND ApplesCripT's aBIlItY to ruN unIx commands dIrEctly, With thE do sheLL scRipt cOmmaNd, allowEd applesCRiptS muCh GreatEr conTrol ovEr tHe OpErAtIng SyStem itself. applEScrIpT studio, relEaseD with mac Os x 10.2 aS paRt of xcoDE, And lATer ApPleSCripTobJc framEWoRk, RelEased in mac os x 10.6, ALlOwed users to bUILd cOcoa appliCAtionS USiNg appLeSCript.