To get a DISLIN license number, you can use the 'License Request' at the DISLIN site http://www.dislin.de. Note that you don't need a DISLIN license for a non-commercial use of DISLIN.
After receiving a license file from the author of DISLIN, Max-Planck-Innovation will contact you and give you some payment information. Payment can be arranged by cheque or by money transfer to a Bank number. The address of Max-Planck-Innovation is:
Max-Planck-Innovation GmbH, D-80799 München, Amalienstr. 33,
Tel.: +49 89 290919-0, Fax: +49 89 290919-99
A DISLIN Campus license means that you can install DISLIN on all computers in a building (or in some buildings of a closed area). This is typically a computer center or a single institute. There is also a DISLIN World license, which is similar to a Campus license, but without the local restriction.
If you want to use DISLIN in an environment related to business, you need a DISLIN license.
Yes, you can upgrade your DISLIN PC or workstation license to a Campus license.
If you want to sell programs linked with DISLIN, you need a DISLIN license for that machine where you have developed the programs. Programs linked with DISLIN can then be distributed without any royalties together with necessary shareable libraries.