When should we start dropping support for older .NET versions

[sebastienros]

Right we ship for 8 (LTS) and 9 (STS) because we want to support the latest version and also an LTS one (8). This was due to the fact that LTS (8) would be supported even after the current STS (9). Since recently this is not the case anymore: c.f. https://endoflife.date/dotnet

I would like to start a discussion about dropping older .NET versions support more quickly that we used to.

• Option A: Support one version (the latest) some time after it ships. For instance 9 today, and .NET 10 three months after it ships. (simplest)
• Option B: Support two versions, as soon as new ones are available, 8-9, 9-10, 10-11. (slower velocity)
• Option C: A mix: Both latest versions for some time, as soon as a new one ships, then drop the previous after a while. Example: 9 today, 9-10 when 10 ships, 10 in 3 months. (more work, all the time)
• Option D: Always target the latest only. (in main, release/x would still target the one they shipped for)

Are there reasons you wouldn't not be able to migrate from one version to the new one since STS and LTS now end at the same time and will get the same patches.

[hishamco]

I vote to support the latest LTS and STS: .NET 10.0 & .NET 9.0

[Piedone]

I've just seen this now. My only concern is forcing people to update .NET (pulling requirements for their dev and hosting environments, potentially also dependencies with it) sooner. E.g., with the current approach, you needed to update .NET with 1.8 (which dropped .NET 6 and 7 support for 8) and will need with 3.0.0 (if we, following the patterns of before, only have .NET 10 support). In a faster approach they'd have needed to move to .NET 9 around 2.1.0. Obviously, you still need to move the same "distance" ultimately, just jumping from 8 to 10, but you aren't forced to update once a year, only every two years.

But otherwise, with the new .NET support policy I don't really have a counter argument against keeping OC on the latest version at all times, i.e. Option D. Support would still be there for minor and patch versions.