[didgetmaster]

Speaking of license options, even if you decide to release all your code as open source, there are so many options to choose from. I counted 116 different open source licenses that are currently 'blessed' by OSI: https://opensource.org/licenses/alphabetical How do you pick the 'right one' for your project that you won't regret later on?

[MichaelCollins]

Look at what other similar projects have been doing, and if it's been working out well enough for them. And if you are the sole copyright owner, you're not locked into your choice. You can either refuse community contributions or make them sign over the copyright to you. Then you're free to distribute your software under another license going further.

Proprietary software doesn't save you from having to make decisions like this. Proprietary software can be licenced under many different terms. Are you going to sell perpetual per-seat licenses? Subscriptions? Selling updates? Support contracts? Avoiding future regret is always going to be a speculative affair.