E-Government can be defined as “carrying out government business transactions electronically”. One aspect of e-government are online law documentation systems. In the Austrian Federal Dataprocessing Center (Bundesrechenzentrum), we have two online law documentation applications under development and support: Electronic custom-law documentation system (EZD) and electronic tax-law documentation system (ESED). EZD has been running since 1995, ESED is currently in a prototype state. The customer of both systems is the IT-section of the ministry of finance. These two applications have been developed especially for the use in the administration and are available for the staff in the Austrian government intranet. In the concrete paper, we will discuss technical and organisational aspects of the online tax-law documentation system ESED which in the first step will be used in the tax department of the ministry. The ministry of finance is responsible for ESED project management. Bundesrechenzentrum is responsible for the technical realisation of ESED.