Notes and Domino are still sold by HCL, but the market for people who can write LotusScript or understand a Notes data model has gone. Firms with decades of records in Notes databases find that every modernisation vendor wants to start from a blank database, which means paying to throw the records away.
I spent thirteen years inside one firm's Lotus Notes estate, first building inside it so their investment was not thrown away, then lifting the records into SQL Server when the time came to put a client portal on top. Both are options. Which one is right depends on what the records are worth to the business and how the firm actually uses them.
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.
FoxPro. Yes, still. And the business still depends on it.