Introducing the Angular Compatibility Compiler
The source code of Angular libraries is compiled before it is published on a package registry such as npm. Until Angular version 12.0, it was not possible to compile Angular libraries using partial Angular Ivy compilation; they had to be compiled with the View Engine compiler. As part of a transition period, Angular uses the Angular Compatibility Compiler to allow Angular Ivy applications to use libraries that are compiled using the View Engine compiler and published to a package registry.
As of Angular version 12.2, the Angular Compatibility Compiler is still included as part of the Angular CLI, meaning that our Angular Ivy applications can consume libraries that are compiled using either the View Engine or the Angular Ivy compiler.
In Angular CLI version 12.0, partial Ivy compilation for Angular libraries was introduced. In short, it compiles all Angular-specific code except component templates. However, partial Ivy compilation...
