Countries not belonging in this category are sometimes euphemistically called developing nations, underdeveloped nations, or, in extreme cases least developed countries. Other terms sometimes used to describe the dichotomy are first world/third world (the second world was once reserved for Communist countries), North/South, or industrialized countries/non-industrialized countries. The term Western countries has similar, though not identical, connotations.
According to the UNEP DTIE OzonAction Programme[1], memberships of OECD and the United Nations Human Development Index for 2003, the following countries are considered developed nations.