"under development" vs. "in development"

[nilsca]

Hi

I'm involved in software development and once in a while we're talking about things that are being developed at the moment. I've seen both of the following 'headers' for things that are being created:

Under Development: Another great feature that ....

In Development: Here's a quick status updated on ...

What's the appropriate expression?

Thanks
Nils

[Casiopea]

They are synonyms to me.