Common Ground

File Format
Name	Common Ground
Ontology	Electronic File Formats Document Common Ground
Extension(s)	.dp
MIME Type(s)	application/commonground
Type Code	CGDC
Released	1993

Common Ground from No Hands Software, allows any Windows or Mac program to create a document that can be viewed or printed by others even if they don't have the program that was used to create the document in the first place. Software comes with a document maker and a viewer. An early competitor to Adobe Acrobat, Common Ground was used to create portable, self-contained documentation applications, called "Digital Paper."

Acquired by Hummingbird Communications Ltd in 1996, then sold to OpenText in 2006.

File Identification

Common Ground version 1 files have Type CGDC and Creator CGVM

Self Launching files have Type APPL and Creator CGSL

Starting at byte 8 file header contains the string CGDC

Later versions have the file header starting at byte 8 DPL2 or DPL3

Screenshots

Sample files

• dexvert samples — document/commonGround
• DP Sample files
• CGUGMAC.DP

References

• Common Ground beats Acrobat to the Macintosh market - InfoWorld 1993
• SOFTWARE COMBINES POWER OF GRAPHICS WITH THE EASE OF E-MAIL - Washington Post 1993
• SMUG article 1994
• The Paper Case - MacWorld April 1995
• https://preservation.tylerthorsted.com/2023/10/20/common-ground/