https://steemit.com/witness-category/@holger80/code-review-of-changes-since-0-20-5-resource-pool-delegations-were-added
https://steemit.com/hf20/@edicted/hf20-pay-to-play-and-rc-pools
RC delegation pool objects and operation were added.
New class rc_delegation_pool_object
Represents a delegation pool.
New class rc_indel_edge_object
Represents a delegation from a user to a pool.
New operation delegate_to_pool_operation was added
This operation can be used to delegate RC from an account to a pool.
Arguably Delegation Pools should have been a part of HF20. Better late than never. This tech will not only make it possible to delegate resource credits separately from upvote power but allow those credits to be shared by a pool so none of the credits sit around getting wasted on a large scale. Instead of having to single handedly delegate users RCs on an account to account basis, we can simply add them to a pool we control.
I only have around 3000 SP, but if you assume the average person only uses 30 SP on average that means I can personally allow 100 users to interact with the blockchain as much as they want. This is a great thing because it implies that the Steem blockchain is delegating responsible resource spending to everyone with stake. Suddenly, I become the one responsible for making sure users aren't abusing the pools that I control.
Anyone can control, anyone can delegate.
Anyone can create a pool and anyone can delegate to that pool. This will create a lot of interesting situations. Maybe I start paying someone a dollar a week to delegate to my pool so I can start claiming 'free' accounts. Maybe I create a pool that users are only allowed to draw from if they are using an app I made. I am quite certain this feature will be hard-coded in the future.
Perhaps there will also be other useful options we can set on pools. For instance, do you want users to only draw from your pool if their own RCs are depleted? Or do you want RCs to be drawn from your pool immediately? (Leaving a personal buffer for each person in it.)
Conclusion
All the outrage from HF20 is about to fade away into obscurity. RC pools will allow anyone to operate on the blockchain as much as they want for quite some time. We are going to have to onboard millions upon millions of users before this becomes an issue again.