When something is labeled "under development," it means that it is a work in progress. There are several different synonyms for this phrase, including "in progress," "under construction," and "being built." Other options might include "evolving," "developing," "unfolding," or "in the making." Each of these phrases suggests that something is still being created or improved upon. "Under development" might be applied to new software, a new business, or a new residential community, among other things. However, by using an alternative phrase, different connotations can be added to the situation, emphasizing time, growth, or progress, for example.