Ask HN: Advice on creating a POS system?

[pj]

I've created an awesome database application that is great for small businesses and one of the niches I'm considering selling it to are retail stores that want to put their inventory online.

This market is dominated by POS software systems. Every retail org has one, just about. I was wondering if any of you have created a POS system and whether or not it is difficult to create this type of functionality for an inventory management system.

Anything I need to think about or resources you can recommend?

[there]

slightly different scope, but i had a customer that owned a couple restaurants and had a custom POS written in vb.net that they were trying to turn into a product to market to other restaurants. it was very poorly written and their developer eventually bailed on the project, but it had everything from food order entry screens, to food supply inventory, to employee management and interfacing with a badge/swipecard printer, to a map editor for the layout of the restaurant to be able to track which waitresses had which tables.

what have you seen in POS systems that you didn't like that would make you want to create a new one?

http://checkoutapp.com/ looks like a nice system for a mac-based store.

[ganley]

Every market is dominated by POS software systems. Oh, you meant something else by "POS".

[drobilla]

The dual meaning of this acronym is always hilarious :)

[fburnaby]

If you want a POS, write in some erlang.