Is there a legal issue when providing API-compatible services? By API-compatible services, I mean developing systems and providing solutions to customers that mimic other existing cloud computing products. With this approach, a new vendor[the one copying the API] can get more adoption for their products/services since it is generally adopted already by customers of big cloud computing companies (e.g Google, Amazon et. al)
For example, Amazon S3 is a storage service powered by S3 API and a lot of services offers compatible API
Wasabi (https://wasabi.com/) -- Wasabi is a company providing a cloud storage solution that is compatible to Amazon S3 API, they offer the solution as a more affordable alternative to Amazon S3 itself.
Minio (https://min.io/) -- Minio is both a company and open-source project, they also provide a cloud storage solution that is Amazon S3 compliant, similar to Wasabi but also provides the Minio platform as an opensource project in Github.
to list a few.
Another example and scenario are for Amazon Cloud Computing solutions (mainly knows an AWS) however in this case instead of directly providing the "API-Compatible" solution as a hosted solution, it is provided as a product customers can host for themselves and the company listed below, Appscale, provides paid support:
- Appscale (https://www.appscale.com/) -- originally Google App Engine (GAE) compatible API, and now AWS compatible service, Appscale develops products and provides paid support.
- Appsclae GTS (https://github.com/AppScale/gts) -- formerly just Appscale this is the product that is Google App Engine compatible and Appscale provides paid support for this product.
I want to ask why such companies are able to provide such web services without facing legal issues and/or termination of web services. Is it generally acceptable to provide API-compatible products and/or web services (either closed-source[like Wasabi], open-source[like Appscale] or both[like Minio]), does it promote "fair-use"?