Complex sentence: It is based on the POSIX specifications, the Single UNIX Specification, and other open standards, and also extends them in several areas; but there are some conflicts between the LSB and The POSIX standards.
Split into simpler sentences: It is based on the POSIX specifications, the Single UNIX Specification, and other open standards, and also extends them in several areas. There are conflicts between the LSB and The POSIX standards.