Hello Chris, Remember me!
I do understand the problem. I do not have a simple answer.
PowerVS can be used for access to AIX for a few pounds a day - less than the price of a fancy coffee. I have a series of YouTube videos covering the theory and hands-on details: Nigel on PowerVS YouTube series But that would add up to £700 per year.
To reduce cost when you do not need you need the LPAR: shutdown AND delete the LPAR. You can keep your AIX disk, remake the LPAR later and attach the disk to get you compilers, code and testing stuff back. A small disk costs a few pence per day. I think the minimum is 30 GB. The default AIX images comes with the AIX toolbox installed so that can help with the open source compilers. I am not sure about getting xlc - which I think has to be paid for.
The alternative is your friend develops friends - like you say a Business Partner, might be able to help with remote access but there is not program or process that I know about. * Warning shameless advert: For my nmon, njmon and ntools - I have friends at a German leading IT service provider called SVA. They use njmon and let me have remote access to AIX and Linux servers (Power and x86). They are an excellent company including testing my code and offering ideas. *Warning end*
If your friends open source project is famous, popular and is likely to drive IBM hardware purchase then you might find there is more official support from IBM.
Perhaps, some one that uses the open source code could pay the PowerVS bill for you and that is a simple transaction - it can avoid legal or security issues or serious long term commitment.
I hope someone else comments on other alternatives.
Cheers, Nigel @mr_nmon