Gibson Office Spreadsheet Software.
Written by Michael Gibson
Maintaining Since 2010

Free office spreadsheet software for:
- Apple Mac OS
- Atari 8-bit [48k or greater required]
- C64
- Linux OS
- TI-99/4A [48k or greater required]
- Windows


Spread Sheet Software:
- GSS T2 for Atari, C64, and TI-99/4A
- GLASS and GSS 1.0 for Mac OS, Linux, and Windows



Written in BASIC and C code.

The original GSS 1.0 file format was released under the GPL 2.

. . . Linux CLI GLASS
- GLASS for CLI source and EXE
-- Version 0.8.2 GLASS_0_8_2_oct_9_2025_Linux.tar.gz GPL3

Windows 64 CLI GLASS
- GLASS for CLI source and EXE
-- Version 0.9.0 GLASS_0_9_0_oct_17_2025_win32.zip GPL3

The GTK 2 GLASS Interface development is being retired.
The last two GTK GLASS source files:
- version 0.5.0 - gtk_intf-05-05-10-20-21.c
- version 0.5.0 - readdata-05-05-10-20-21.c

- Manual for Glass

You can manually edit the GSS file:
GSS 1 file format

Test Book 1 in GSS 1.0 format. Win64 Screen shot of running book1.gss
Test Book 2 in GSS 1.0 format. Win64 Screen shot of running book2.gss
Linux Screen shot of running book2.gss

GSS T2 file format - documents coming soon.

Advantages of GSS 1 (lite) system and files?
- light weight
- formula standards
- 93 columns, 93 rows.
- General purpose SS
- Scrollable text display


Advantages of GSS T2 system and files?
- light weight
- Data Model information
- 20 columns, 30 rows
- Made for low resource computers.
- SS aimed at financial user
- Scrollable text display

. . . TI-99/4A GSS requires:
- 32K Expansion board or 32K Expansion side module.
- TI Extented BASIC
- One or more Cassette drives and/or disk drives
- Currently only uses GSS T2 file format

- TI-99/4A source code GSS version 0.9.25.A under GPL 3 - Oct 3 2025
- TI-99/4A screen shots.