you register more than one company and do the accounting for each one at the same time. It's also a multi-tasking application, with which you can even control who can use it and save reports with an Excel extension.
It also includes tools to keep the book entries, balances, losses and profits, budgets, and inventory, as well as search by concept and amount, create statistics, and print official Excel templates, etc.
ContaSol also has other great features, too, such as a calendar, calculator, address book, etc.