How to choose ThreadSafe and NonThreadSafe for php isapi and FastCGI running

How to choose ThreadSafe and NonThreadSafe for php isapi and FastCGI running Php versions are increasing, and there are inevitable questions about version selection.

The version of VC9 is compiled with legacy VS 2008,

VC6 is compiled with legacy VS6.

If you are using IIS + PHP in windows, you need to download the version of VC9.
If you are using Apache + PHP in windows, you need to download the VC6 version.

NT (Non-Thread Safe) indicates Non-Thread security, and ts (Thread Safe) indicates Thread security.

PHP has two running modes: ISAPI and FastCGI.

The ISAPI is executed in the form of a DLL dynamic library. it can be executed after a user request. after processing a user request, it will not disappear immediately. Therefore, thread security check is required, in this way, the program execution efficiency is improved. if you use ISAPI to execute PHP, we recommend that you select the Thread Safe version;

FastCGI executes operations in a single thread, so it does not need to perform thread security checks. apart from the thread security check protection, it can improve the execution efficiency, if you use FastCGI to execute PHP, we recommend that you select the Non-Thread Safe version.

For apache servers, isapi is generally used, and FastCGI is used for nginx servers.