Excerpted on 2005/08/01 from
http://www.mediacrypt.com/_contents/20_support/204010_faq_bus.asp :

What license do I need?

The non-commercial use (tests, pilot installations, private use,
etc.) of IDEA is free of charge. If you want to use IDEA commercially,
a license is required. Two types of licenses are available:

End-User License - use of IDEA with hardware and software products
(e.g. PGPi, etc.). Single End-User Licenses, as well as Server
End-User Licenses for server-based applications are available.
Single End-User Licenses are available online via our website.

Product License - integration of IDEA in hardware and software
products (e.g. smart cards, encryption applications, etc.). Different
Product Licenses are offered for Media Broadcast (broadcasting,
multicasting, etc.) and General IT (banking, telecom, data transfer,
etc.) applications.

When do I need a Single End-User license?

A Single End-User license is needed when the IDEA executable code
is installed once on a client or end-user device (PC, workstation,
PDA, pager, "smart phone" or other electronic device for which the
IDEA executable code was designed), and used by one individual/user
at a time.

When do I need a Server End-User license?

A Server End-User license is needed when the IDEA executable code
is installed once on a device and is (or can be) executed by many
individuals/users at the same time.

Can I use IDEA with the freeware program GnuPG?

Yes, GnuPG contains links to include the IDEA encryption algorithm.
Non-commercial use is authorized according to our Licensing Policy.
If you use IDEA for commercial purposes with GnuPG you would need
to order an End-User License. Should you need a license for a
server-based implementation of GnuPG, then we suggest to order a
Server End-User License.

I am using GnuPG as a single user. What license do I need?

In this case you need a Single End-User License. Single End-User
Licenses can be purchased directly from our website via credit card
(VISA/MasterCard). Alternatively you can pay by check, money order,
or wire transfer (for a small fee).

I am looking for a license for a group of users using GnuPG on a
server. What license do I need?

If you want to use IDEA commercially in a server based application
you will need a Server End-User License. The price of the license
depends on the number of users having access to the server-based
application. Contact us for details.

I am using PGP 2.6.3i. Do I need to purchase a license?

PGP 2.6.3i may be freely used for non-commercial purposes only.
If you want to use PGPi for commercial purposes, you need to buy
a separate license for the IDEA algorithm used in PGP. IDEA licenses
can be purchased directly from our website via credit card
(VISA/MasterCard). Alternatively you can pay by check, money order,
or wire transfer (for a small fee).

What is the definition of non-commercial use of IDEA?

The free use of software and/or hardware containing the algorithm
is strictly limited to non revenue generating data transfer between
private individuals, i.e., not serving commercial purposes. Requests
by freeware developers to obtain a royalty-free license to spread
an application program containing the algorithm not for commercial
purposes must be directed to MediaCrypt.  Non-Commercial is not
equal to non-profit. A non-profit organization using a tool for
running its business still remains a commercial organization and
is object to a license.

What is the definition of commercial use of IDEA?

Any use of IDEA commercially (in paid or free product) is object
to a license.  Commercial Purposes' shall mean any revenue generating
purpose including but not limited to

a) using the algorithm for company internal purposes (subject to
a Server License) b) incorporating an application software containing
the algorithm into any hardware and/ or software and distributing
such hardware and/or software and/or providing services related
thereto to others (subject to a Product License).  c) using a
product containing an application software that uses the algorithm
not covered by an IDEA license (subject to an End-User License).

Do educational institutions get a discount? Do they qualify as
"non-commercial"?

Universities using IDEA for research/education purposes, only, will
not have to pay for licenses. If IDEA is used for administrative/internal
tasks a license is required.