1. SPREADSHEETS

2. What is a spreadsheet?
a computer application that simulates a paper accounting worksheet
displays multiple cells usually in a two-dimensional matrix or grid consisting of rows and columns
frequently used for financial information because of their ability to re-calculate the entire sheet automatically after a change to a single cell is made

3. Paper spreadsheets
"spreadsheet" came from "spread" in its sense of a newspaper or magazine item (text and/or graphics) that covers two facing pages, extending across the center fold and treating the two pages as one large one
The compound word "spread-sheet" came to mean the format used to present book-keeping ledgers —with columns for categories of expenditures across the top, invoices listed down the left margin, and the amount of each payment in the cell where its row and column intersect

4. Early implementations
Batch spreadsheet report generator
LANPAR spreadsheet compiler
Autoplan/Autotab spreadsheet programming language
APLDOT modeling language
VisiCalc
Lotus and other MS-DOS spreadsheets

5. Batch Spreadsheet Report Generator
dealt primarily with the addition or subtraction of entire columns or rows (of input variables) - rather than individual 'cells‘
One implementation is the Business Computer Language (BCL) which was used in IBM 1130 in 1962
In the late 60's Xerox used BCL to develop a more sophisticated version for their timesharing system

6. LANPAR spreadsheet compiler
Stands for LANguage for Programming Arrays at Random
was conceived and entirely developed in the summer of 1969 following Pardo and Landau's recent graduation from Harvard University
was used by Bell Canada, AT&T and the 18 operating telcos nationwide for their local and national budgeting operations
was implemented on GE400 and Honeywell 6000 online timesharing systems enabling users to program remotely via computer terminals and modems

7. Autoplan/Autotab spreadsheet programming language
Developed by A. Leroy Ellison, Harry N. Cantrell, and Russell E. Edwards - founder of Capex Corporation
"AutoPlan" ran on GE’s Time-sharing service; afterward, a version that ran on IBM mainframes was introduced under the name "AutoTab“
was not a WYSIWYG interactive spreadsheet program, it was a simple scripting language for spreadsheets

8. APLDOT modeling language
An example of an early "industrial weight" spreadsheet
developed in 1976 at the United States Railway Association on an IBM 360/91
as used successfully for many years in developing such applications as financial and costing models for the US Congress and for Conrail
was dubbed a "spreadsheet" because financial analysts and strategic planners used it to solve the same problems they addressed with paper spreadsheet pads

9. VisiCalc
implemented by  Dan Bricklin and Bob Frankston on Apple II in 1979
the first spreadsheet that combined all essential features of modern spreadsheet applications, such as WYSIWYG interactive user interface, automatic recalculation, status and formula lines, range copying with relative and absolute references, formula building by selecting referenced cells
the first "killer app", an application that was so compelling, people would buy a particular computer just to use it

10. Lotus 1-2-3 and other MS-DOS spreadsheets
Loturs 1-2-3: released in January 1983 and replaced Visicalc
Microsoft Excel: starting in the mid 1990s continuing through the present, Microsoft Excel has dominated the commercial electronic spreadsheet market
OpenOffice.org Calc: a free, open-source program modelled after Microsoft Excel
Gnumeric is a free cross-platform spreadsheet program that is part of the GNOME Free Software Desktop Project

11. Web-based spreadsheets
Ajax circa 2005
 Office Web Apps
Google Spreadsheets
The above online spreadsheets have strong multi-user collaboration features and / or offer real time updates from remote sources such as stock prices and currency exchange rates