Adobe’s Common Extensibility Platform, or CEP, is a suite of technologies embedded in Adobe’s Creative Cloud (CC) desktop applications. CEP was originally known as CSXS—it first appeared as part of Adobe Creative Suite 4 in 2008.
CEP delivers a runtime environment that is integrated with the ExtendScript scripting support of the host application. CEP is implemented in Creative Cloud applications, including InDesign, Photoshop, Illustrator, Premiere Pro, and Dreamweaver.
Finally, CEP integrates the Adobe IPC Toolkit, an interprocess communications system for Adobe CC applications. Like CEP, the Adobe IPC Toolkit is enabled by PlugPlug. With the IPC Toolkit, you can, for example, control Photoshop or Illustrator from an InDesign extension.