[jcnnghm]

Quickbooks sucks in a major way. If you could come up with a simple accounting system that didn't take three full minutes to load, even with an SSD, 4 processing cores, and 8GB of memory, you'd have a winner. Even if your software was really bad, it would probably still be better than Quickbooks.

You'd probably have to support these basic features:

Write Checks

Track Account Balances and Transactions - These need to be able to be imported in standard formats. The format Quickbooks uses is XML. I found it simple enough to reverse engineer that I was able to convert CSV dumps from my bank to QBO files and get them importing into Quickbooks.

Categorize Transactions - I need to be able to say what each transaction is. I should be able to setup filters to automatically categorize imported transactions. For example, at the convenience store Wawa, I buy exactly two things, coffee and gas. If the transaction is less than $5, I want it to be categorized as personal food, if it's over $20, I want it to be categorized as gas. I should be able to set this up, and never have to categorize one of these transactions again.

That's all it would really take. You would probably want to integrate with one or more invoicing systems to track receivables. You could setup an API then build connectors for popular applications, like Freshbooks. A good interface for accounting for bank deposits would be helpful as well.