how can I get web services to retrieve accounting ( busy accounting software ) data into web based application?
I am developing a web based application (using PHP) which require retrieval of live data from busy accounting software. how to create web service to retrieve busy accounting data?. do busy provide any support?
Where would this question fit?
That question is too broad at the moment I'm afraid to be answerable anywhere. It seems to invite to provide you with a tutorial / high level approach.
If you're more into the whiteboard phase of designing a software solution, maybe Software Engineering could be a helpful resource but you need to be specific about the capabilities of your accounting software and what is keeping you from creating the webservice.
If you have a specific problem with either creating or calling a webservice (so you have build something but it doesn't work (doesn't meet certain requirements, throws runtime errors, won't compile, won't be configured correctly) you can ask on Stack Overflow
When you have working code but you need an extra pair of eyes to improve on code structure or performance Code Review might be a fit.
The correct source for information is your vendor. Nobody here can tell you what your vendor supports or will support in the future. It's not a matter of what SE site you pick. None of them are qualified for this question and all of them should close it.
Now once you talked to your vendor and they told you what they support, if you have technical problems doing that on your end, only then you can see if it's more of a design or coding issue and pick the SE site best suited.