Prosper is an economy plugin built as a full systems project rather than a simple balance command wrapper. It includes wallets, bank accounts, dynamic item pricing, chest shops, auctions, loans, sell wands, automation, economic events, transaction history, and multiple storage backends.
It also shows a strong interest in simulation and operator tooling: price decay, market events, item price import/export, auto-buy and auto-sell rules, leaderboard and display systems, and support for YAML, SQLite, MySQL, MariaDB, and PostgreSQL all matter when you want a server economy to behave like more than a static price sheet.
It is a good example of blending gameplay systems, persistence, admin tooling, and economic balancing into something that feels like a real server subsystem rather than a handful of commands around a number in a database.