Original version of GCL was developed by Zeta Inc., NPO URAP and Eigo UEHARA.

Current version is developed by Zeta Inc., NPO URAP, Eigo UEHARA and Masami ISODA.

International version is developed by Masami ISODA, CRICED, University of Tsukuba.

Distribution rights within Japan are held by Zeta Inc.
http://www.zeta.co.jp/

Distribution rights outside Japan are held by CRICED, University of Tsukuba.

The international version of dbook can be obtained at the following location:
http://math-info.criced. tsukuba.ac.jp/software/

The use of the international version of dbook is limited to non-commercial purposes
outside Japan only. For commercial uses of GCL, please contact Masami ISODA,
CRICED, University of Tsukuba.

Publications that include contents based on the international version of dbook are
required to acknowledge the authors using the following sentences:

“Parts of this work have been produced using the international version of GCL, developed by CRICED, University of Tsukuba, Zeta Inc., and NPO URAP, Japan. Copyright and distribution rights of the international version of GCL outside Japan are held by project director Isoda, Masami, CRICED, University of Tsukuba.”

Japanese manual is written by Uehara, Eigo; English manual is edited by Hiroki YAHARA with support of Peter SURANYI.

This on-line manual was designed by Yukie HORI.