In plain English
Self-hosted means the software runs on a server you rent and control yourself. A VPS (virtual private server) is that rented server. Bank sync pulls transactions from your bank automatically. Source-available means you can read and run the code, and the licence restricts some uses, such as offering the software as a paid service.
I spent the last two days preparing my Q3 tax pack for my accountant with two self-hosted tools: Actual Budget and Invoice Ninja, on an IONOS VPS that costs £6.05 a month. The same server runs my CRM, n8n and an RSS reader.
Years ago I paid FreshBooks about $25 a month, and its bank syncing always broke. In September I replaced MoneyWiz with Actual. My agents matched bank transactions, chased unpaid invoices, categorised and tagged spending, and flagged mismatches. They searched my email to reconcile payments and sorted personal expenses from business ones.
My accountant still does what she needs to do with the work. I hand it over as prepared as I can make it, with everything reconciled against my accounts first.
Actual's bank sync for European banks runs through Enable Banking, which I turned on as an experimental feature. Invoice Ninja is source-available under the Elastic License: I can read the code and run it on my own server. The licence limits some commercial uses. I paid for its white-label licence to remove the branding and to support the software.
If you run a small business, already pay for a mid-tier ChatGPT or Claude plan, and also pay for invoicing, CRM or finance software, start looking at open-source replacements and have your agents maintain them with you. You might end up saving a lot of money.