What is Employeur D?

The term "Employeur D" is quite vague and appears to simply mean "Employer D" in French. Without more context, it's impossible to provide a specific technical explanation. It likely refers to a specific employer organization (company, institution, etc.) whose name begins with the letter 'D'. It doesn't represent a specific technology in and of itself. To get a relevant description of any technologies used, you would need to know the specific organization being referenced, as technologies employed would vary greatly depending on the employer's industry and activities.