MARC Standards - Library of Congress Network Development and MARC Standards Office. Includes: general information, MARC documentation, MARC Advisory Committee, MARC SGML, records and systems, and software and utilities.

Bibliographic Formats and Standards - An exhaustive guide to the MARC standard from OCLC.

Book Cataloger's Cheat-Sheet - A fast guide to cataloguing an item in MARC format. Provides a concise guide to abbreviations and field tags used.

MARC 21 - MARC formats for the 21st century - Represents the continuation of the CAN/MARC and USMARC formats in a single edition with a new name.

MARC Specialized Tools - Provides links to MARC vendors who market specialized tools that provide enhanced usability to MARC 21 records and systems. Includes both commercial and free tools.

MARC Standards - Serves as the common standard for the exchange of machine-readable authority, bibliographic, classification, and holdings data in Canada. Includes news and announcements, CAN/MARC documentation, MARC Records Distribution Service (MRDS).

MarcEdit - MarcEdit is a free windows based MARC editing tool, that provides methods for converting MARC to text, Text to MARC, MARC to XML and MARC to Dublin Core.

MARC.pm : Machine Readable Cataloging Perl Module - A free Perl module for processing MARC records.

Tag of the Month - A guide to most MARC cataloging tags with examples and text explaining their usage. Useful to persons needing plain descriptions of MARC fields. From Follett Software Company.

UNIMARC - Universal Bibliographic Control and International MARC Core Programme (UBCIM). International Federation of Library Associations and Institutions.

XML and MARC - Stanford University's Lane Medical Library details its experiment in using XML instead of MARC to organize its catalog data.