Shim (computing)

Formally, "a polyfill is a shim for a browser API".

Shims for older APIs typically come about when the behavior of an API changes, thereby causing compatibility issues for older applications which still rely on the older functionality; in such cases, the older API can still be supported by a thin compatibility layer on top of the newer code.

Wrapper libraries (or library wrappers) consist of a thin layer of code (a "shim") which translates a library's existing interface into a compatible interface.

In the context of DOS and Windows, the term stub is also used in a fashion like shim to describe the small areas of interface code left in conventional memory by self-relocating resident drivers which move most of themselves into upper memory, the high memory area, expanded or extended memory as well as similar stubs to allow the relocated code to communicate with real-mode DOS in conjunction with DOS extenders (like DPMI, DPMS, CLOAKING or NIOS).

They are called thunking and shimming.

In computer programming, a shim is a library that transparently intercepts API calls and changes the arguments passed, handles the operation itself or redirects the operation elsewhere.

In computer programming, a shim is a library that transparently intercepts API calls and changes the arguments passed, handles the operation itself or redirects the operation elsewhere.

In computer programming, a shim is a library that transparently intercepts API calls and changes the arguments passed, handles the operation itself or redirects the operation elsewhere.