I just started using Greenshot, and think it's a great program. One request I have for future versions is to see if it can use less memory. On my WinXP SP3 it uses 100-150 MB of memory.
Thanks for your feedback. As we are frequently asked about RAM usage, and there are often misunderstandings regarding this complex topic, we have put together an FAQ entry regarding memory usage. You might want to have a read, it includes some information worth considering, e.g. maybe the memory usage is actually less than you think and there's an option to minimize the memory footprint.
If you still have questions, please let us know.
Thanks and best regards,