Our VS extension still needs to support VS 2005 and 2008, but I cannot generate a VSPackage PLK anymore - the system seems to be either broken or no longer supported by Microsoft. There is an MSDN page: How to: Obtain a PLK for a VSPackage, but steps described there no longer work on the new VS Extesibility website. Does anybody know whether creation of new VSPackages (signed with PLK) is still supported for VS 2005 and 2008? If so, where to go for the PLKs?
Enroll the VSIP Program (https://vsipprogram.com). The Basic Level is free. It takes a couple of days to get approval from Microsoft.
Click the "Support" link at the bottom of the main page to go to the FAQ section.
There is a "How do I get a PLK/SLK for Visual Studio?" FAQ entry that points you to the PLK/SLK generator tool.