The 2005 edition of Ed de Moel's book The Annotated M[UMPS] Standards is available on-line in interactive format.
The Annotated M[UMPS] Standards contains an updated version of Ed's older book M[UMPS] by Example. In the newer version, each example is hyperlinked with the corresponding sections of the various M[UMPS] standards. All M[UMPS] standards are included in this new book, the 1977, 1984, 1990 and 1995 versions, as well as the draft MDC version. This book contains the language standards as well as the various versions of Open M[UMPS] Interconnect, the Bindings to GKS and X-WindowTM and the M[UMPS] Windows Application Programmers' Interface.
The examples are still on-line. The easiest way to get there is from the
Annotated Standards pages.
Click on the above link to start, that link gives access to all the on-line standards. For many pages in the standards, there is a button labeled "examples" that leads to the examples for that part of the standard.
The old version of the "Examples" book is still available at: http://220.127.116.11/MDC/example/index.htm. However, that version is no longer maintained.