whether the keil software and embedded c are platform independent or dependent

With compilers, there are (at least) two platforms involved:

1. The Host plaform = the platform on which the compiler itself runs;

2. The Target plaform = the platform on which the generated code runs.

When the Host & Target platforms are the same, the compiler is called a Native compiler;
When the Host & Target platforms differ, the compiler is called a Cross-compiler.

Keil compilers are all cross-compilers: they run on Windows hosts, and generate code for other Targets.

As they don't run on non-Windows platforms, they are platform-dependent in that sense.

Similarly, each Keil compiler generates code for only a specific "family" of target architectures - so they are also platform-dependent in that sense.

But Keil C51 generates code for any Target using the 8051 architecture; it is not confined to any specific 8051-based target - so it is platform-independent in that sense! Similarly for the other toolsets.

With compilers, there are (at least) two platforms involved:

1. The Host plaform = the platform on which the compiler itself runs;

2. The Target plaform = the platform on which the generated code runs.

When the Host & Target platforms are the same, the compiler is called a Native compiler;
When the Host & Target platforms differ, the compiler is called a Cross-compiler.

Keil compilers are all cross-compilers: they run on Windows hosts, and generate code for other Targets.

As they don't run on non-Windows platforms, they are platform-dependent in that sense.

Similarly, each Keil compiler generates code for only a specific "family" of target architectures - so they are also platform-dependent in that sense.

But Keil C51 generates code for any Target using the 8051 architecture; it is not confined to any specific 8051-based target - so it is platform-independent in that sense! Similarly for the other toolsets.