Originally I thought of this as lifetime income for retirement, but there’s no reason it should be limited to retirement. If someone has a fixed amount of capital, can it be invested to provide an income for life, no matter how long that is?
The links below cover individual strategies.
S&P500 Payout as Lifetime Income
Constant S&P500 Inflation Adjusted Payout
S&P500 Plus Index Options for Principle Maintenance
S&P500 Plus Protective Put Options for Principle Maintenance
S&P500 Plus Strangle Options for Principle Maintenance