What languages to write windows shell extensions

Question

I know how to write shell extesions in python.
The drawbacks are

• it does not work on 64 bit Windows
• I am unsure how creating a python process everytime something “happens” reduces performance.

I know how to write shell extensions using .Net (C#)
The drawbacks are

• discouraged by MS
• I am unsure how this reduces performance. (does it?)

I have seen shell extenions written in (free)pascal.

• Are there drawbacks using this approach
• Does this work with 64bit windows.

Obviosly one can write shell extensions using c or c++

• Well... I am still trying to understand com in c and c++....

What other optios are there, what other languages ?
Do they have drawbacks?

Answer 1

because explorer is running all the time, please use a language that is efficient and close to the OS as possible. C or C++ please.

Answer 2

Since .NET 4 came along, MS now do support .Net for Shell Extensions, since the major problem (cannot host multiple CLR versions in shell) has been solved through the side-by-side mechanism:

With the ability to have multiple runtimes in process with any other runtime, we can now offer general support for writing managed shell extensions—even those that run in-process with arbitrary applications on the machine. We still do not support writing shell extensions using any version earlier than .NET Framework 4 because those versions of the runtime do not load in-process with one another and will cause failures in many cases.