Writing a Package Manager
I think some day rather than the current paradigm, even including declarative package managers and environments and distros, the future will be per-user and even per-app chrooting or jails, or something similar. Apple already uses something like this today. Many people who are smart about information security have one login for shopping and banking and bill pay, one for their business, and one for cruising the web or gaming or whatever. That way a breach of one doesn't necessarily end up pwning the whole system.I only have two accounts, one "serious" and one "off hours" but I still feel better protected than most people.