OCX, or Object Linking and Embedding, is a protocol that was created by Microsoft. OCX is a tool that will allow the developer to farm out a specific part of the document to another program where it could be edited. Once it was edited, it could be imported back into the original program. For instance, if someone is using a desktop application, they may be able to farm out a portion of the text and transfer it to a word processing software. One of the most powerful benefits of OCX is the ability of the user to create what is called the master file. Once this file is created, the user can set up the system where altered will be effected by changes that are made to the master file. Another powerful advantage of OCX is its relatively small file size.
OCX is a tool that is frequently used for the maintenance of compund documents. However, it can be used for other tasks, and one of the most popular uses for this protocol is to transfer files between various computer programs. This will commonly be achieved through the drage and drop method. The term embedding may be used to refer to placing media files within web pages. Some of these media could be animation or videos. The OCX protocol is known for using what is called a fat client system. What this means is that the file that is being embedded must be located on the machine where the process takes place. To give an example, if a user wants to make changes to a Microsoft Excel file, the Microsoft Excel program must be present on the machine where the user wants to carry out this task.
The very first version OCX was introduced in 1990, and many people considered to be the evolution of what would become DDE, or dynamic data exchange. Microsoft had originally implemented this tool in the older versions of Windows. The biggest disadvantage to DDE is that it was restricted in how much data would be transferred between two programs. In contrast, OCX could process active links among multiple documents and it could also could place one document type inside another document. OCX based servers and their clients will communicate through a process that is dependent on virtual function tables. The VTBL will be comprised of a function pointer that the library can utilize for the purpose of facilitating communication between the client and the server.
Once an OCX object has been added on top of a clipboard, it will be stored in a format that is native to the Windows operating system. An example of these formats could be bitmaps, and the object can also be stored in the is original format. When the object is stored in its original format, it can allow an OCX program to embed a segment of a different document that was either copied or cut from a clipboard. The newer versions of OCX would use elements such as the Component Object Model.