Fun Fact: The PortableApps.com Platform's menu is written in Delphi. We're debating whether to stay with it or not, mainly due to the buy-in costs for developers. We can either use no external bits and let people work with Delphi Starter Edition (free, only for use with free/open source, 32-bit only, no add-on support), convert to Lazarus (open source equivalent of much older Delphi version with many newer bits added), come up with the money to pay for a lot of licenses (unlikely), or rewrite in another language. It's a bit under 10k lines of code, so even a rewrite wouldn't be too painful.
It's also worth noting that while the linked article mentions Windows 7 and up, the current version of Delphi 10.2 produces apps that also work under Windows XP and Vista as well.
I've tried out PortablApps some time earlier, but only briefly, and did not look into the infrastructure aspects. Are you saying that developers who create portable apps need to use Delphi in order to be part of your platform? And if so, why is that?
The main platform's menu is written in Delphi. The tools to package apps (both the AppNamePortable.exe launcher and the installer they are then packaged in) are written using NSIS. Developers packaging most apps can do so just by filling in INI files without writing a single line of code. The utilities include NSIS itself, auto-generate the code needed for the installers and launchers, and automatically compile them.
Have you evaluated any other languages apart from Pascal/Lazarus? If Windows XP+ support is the driving feature and you would consider a modern language then please take a look at Nim[1], it features some Delphi/Pascal-isms so you and your team may find it familiar.
I'm happy to answer any questions you may have about it.
One of the main reasons we settled on Delphi originally is that it was a relatively easy to learn RAD setup for GUI apps with a solid IDE to work in. Nim seems to be command-line, kernel, and server-focused.
I updated my original post to indicate that it's the platform's menu. We refer to the platform meaning the menu, app store/updater, and backup/restore features. Things like the app launcher to make things portable, installer to package, etc are separate from the platform but part of the PortableApps.com ecosystem.
It's also worth noting that while the linked article mentions Windows 7 and up, the current version of Delphi 10.2 produces apps that also work under Windows XP and Vista as well.