Record Research Inc.
Decades of Billboard chart data moved off SQL Server 7, Classic ASP and Visual FoxPro onto Azure, while the books the business sells kept getting published.
Visual FoxPro 9 left extended support in January 2015 and it was the last version. It is still holding data in publishing, accounting and small manufacturing shops, usually in the same building as the one person who knows how to open it.
I moved a chart-data publisher's FoxPro archive and book-generation tools onto Azure SQL, and kept the FoxPro tools running against the new database until their replacements were ready, so the business never stopped. The data comes out first, which is where the risk is; the tools follow.
Your Silverlight application has no browser left to run in, and the people who built it have gone.
LightSwitch built your application. Nobody can change it now.
Delphi is alive. The one person who can read your Delphi 5 program is not on staff.
Your records are in Notes databases. Getting them out without losing them is the job.