I use Delphi. The RAD Studio IDE is super featured and it's really easy to create interfaces. A nice feature is that the programs produced contain all dependencies so nothing else needs to be installed when distributing.
I'm curious if you're familiar enough with other more modern languages and platforms to give an opinion on the relative efficiency of Delphi compared to some of the others? As someone who used to build lots of apps in MS Access (which is similar to Delphi but not as good), I find it takes far longer to build things with modern platforms, although you have much more capabilities.
I do a lot of Delphi during the day (medical systems), also spent a number of years with other languages - C/C++, Objective C, Java, c#, javascript, typescript, lua, perl etc and I agree whole heartedly. Delphi is still the most productive platform imho, so much so that most side projects I do with delphi. The fact it is now cross platform adds to the list of 'why I think delphi is the best'.
Unfortunately there's no one thing that I can point to that makes Delphi the best, its a lot of little things - the IDE and screen painter, the way you can use pointers, deployment is so easy with a single exe, RAD. The one language I prefer to delphi is typescript, it is Delphi with a lot of functional sugar, but since its written by the same guy probably not a surprise.
I used to program in Delphi between 1997-1999 and after that I couldn't get even close in terms of productivity with Java. It wasn't the language though, the strongest thing about the Delphi environment was that it was truly comprehensive and you'd just go in and implement your business logic.
Same here. Funny how, 15 years later, there still isn't a competing language/UI builder that can measure up. Xcode + Interface Builder, for example, is a joke compared to Delphi. The first time I used IB, I remember being horrified by how IB requires you to "connect" UI elements to variables, and how it can't even create those variables for you, let alone allow you to add event handlers.