Official International Industry Standards

Since many years, the core Topic Maps technologies are official standards, published by the International Organization for Standardization. This ensures long term stability, compatibility and consistency. It supports independence from specific vendors this making it suitable also for government projects.

The latest versions (including drafts) of the ISO standards are available on
The most prominent standard is the Topic Maps Data Model which uses XTM 2 and CTM as serialization formats.

Community Standards

Besides the ISO standards, there are some community standards.

Programming APIs

For Java there’s TMAPI – be sure to have a look at the current 2.x version.
There are also versions for PHP: PHPTMAPI and .NET: TMAPI.NET

Serialization Formats


Modeling conventions

Some practices evolved in the community and are not formalized in any standards. Knowing them makes your life easier.

Normalizing Association cardinality

Many binary Associations are easier to handle than one big association with many roles. Consider e.g. a company and its employees. Each employee should have his/her own association to the company and not share one association with all employees in the company.

Directed association names

Directed Names for (bidirectional) associations should be defined as names for the association type topic and scoped with the role type topic of the source role. So the “employs” association with the role types “employer” and “employee” should have a name “employed by” which is in the scope of “employee”. As you probably know: It’s not the association directly having this name but the topic which is the type of this association. This way, all associations having this name benefit from the naming.

More Information

For programmers, many software libraries, called Topic Maps engines are available to use, some of which are part of complete knowledge management solutions.

Students and academics will find the Topic Maps Library useful. It includes many publications, a glossary, information about standards and more.

Many companies offer commercial services and/or consulting around Topic Maps products. The list of sponsors of TMRA is a good place to look for them. The Topic Maps Projects list gives some starting points, too.

The Standards are available through ISO. The latest versions can also be obtained at The most prominent standard is the Topic Maps Data Model which uses XTM 2 and CTM as serializations.