Countability – Correct Usage: ‘These’ or ‘This’ Two Software

As @FumbleFingers points out either is acceptable. I think the distinction is very slight but present and depends on the point the author was making.

If he had used "developments" that would have called attention to the fact that there are several different developments that make up the outer portion of the area. I would have used developments, therefore, if my point was about the fact that these multiple independent developments ultimately cost more than if a single developer had been contracted to develop the whole area (for example).

In this case, though, I think the author was less interested in talking about them individually and just wanted to focus on them collectively. I think the author's point was in the low-rise nature of all the development in that area regardless of who had built which parts. Thus development was used.

Where "business" is being used in a similar context to "company" or "organisation", and as such is countable, you need to make sure you use an article.

It goes into the business as well. He is running a business.

Or:

He has been running the business since day one.

So both of your phrases above require an article.

However, the term "business" can also be used as a concept, describing trade (see its various definitions). In this case it is an uncountable (conceptual) noun, and so no article is needed.

Business is going well at Blah Blah Blah Inc's Headquarters.