Here is a table with the built-in libraries:
|Mac 32-bit PPC||-||OpenSSL||-|
|Linux 32-bit ARM||-||OpenSSL||-|
For all variants you can always optionally load system or custom libraries. It's just about what is included in the plugin as default option.
Native SSL on Mac requires OS X 10.8 or newer.
If no library was loaded and you run the CURL class constructor, we will try to load the system library. That works fine on Linux and Mac.
So now it's your decision what you want to use:
The default for examples will stay with CURLSMBS as the built-in libraries provide cross platform the same experience. If you need to do native SSL, you may want to try CURLNMBS and if you plan to use your own custom CURL libraries, you can use CURLMBS.