LemonPOS

Cloud POS platforms bill a monthly fee per register and store every sale on someone else's infrastructure. LemonPOS keeps the same job — ringing up items, tracking stock, printing receipts — on a MySQL database you run yourself, unchanged since its last release in October 2015.

Where LemonPOS fits

LemonPOS covers the core register loop a small shop needs: barcode lookup, a price-checker mode for customers, sale suspension so a cashier can start one transaction and finish it on another terminal, and printed end-of-day reports. Every terminal talks to the same local MySQL instance instead of a remote API, so checkout lookups happen over the LAN — there's no round trip to a payment provider's servers for a price check or a stock lookup, only for the card swipe itself.

That local-first design is also where the tradeoffs start. A single MySQL server backing every register is fine for one or two lanes and a modest catalog, but nothing here has been tuned or tested against modern MySQL releases, and the script that used to configure the database broke against newer versions. There's no built-in card processing, so cash-forward shops pair it with a separate terminal, and no cloud sync between locations — each site keeps its own database.

What it does well

• Single MySQL database shared by every terminal, so a two-register shop sees the same stock and sales figures without extra sync tooling.
• Sale suspension and resume, letting a cashier park a transaction and complete it from a different till.
• A price-checker mode customers can use on their own, cutting "how much is this" trips to the counter.
• Custom product entry and special orders for items that never made it into the product list.
• Printed close-out reports and an admin screen for inventory and store settings, run by whoever is on shift.
• Hardware support that was actually tested — a parallel matrix printer, a USB thermal printer and a USB barcode scanner are named in the docs, not just assumed to work.
• A themeable interface, useful for an agency skinning one install differently per client site.

Limitations

• The MySQL setup script breaks against current MySQL releases; a fix is documented on Stack Overflow, but it was never merged into the project (GitHub issue #5).