Dear Alireza Ahmadi

If your question is about applications that are based on AI, I can name, for example, the recommendation engine of Amazon, Netflix, Google Docs, and etc.

But if you mean alternatives of OpenAI, it is better to search on CUDA, OpenCL, and etc.

I hope it will be useful.

You can try OpenCL.

Dear Alireza Ahmadi

A modular application is one that is broken into a number of loosely connected functional parts (referred to as modules) that may be combined into a larger application. A client module encompasses a subset of the application's overall functionality and usually represents a collection of related concerns.

Modular programming language examples - All object-oriented programming languages, such as C++ and Java, are modular programming languages.

A web module is a representation of a web application. A web module is constructed by combining servlets, JavaServer Pages (JSP) files, and static content such as HTML pages into a single deployable unit. One or more servlets, JSP files, and HTML files are included in a web module.

Kind Regards

Qamar Ul Islam

https://www.youtube.com/watch?v=SGUCcjHTmGY

here is what I looking for a

replacement for OpenAI platform

I think the best article for your question is:

https://www.simplilearn.com/tutorials/artificial-intelligence-tutorial/artificial-intelligence-applications