9 votes
PI File - What is a .pi file and how do I open it?
Learn about .PI files and view a list of programs that open them.
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Overview
What is a PI file? A PI file is a data file created by iPi, a program that calculates the digits of Pi. It stores the progress of a user's Pi calculation. iPi users can load a PI file to resume the calculation the file describes.
More Information Pi is a mathematical constant that describes the ratio of a circle's circumference to its diameter. Notably, Pi is a never-ending number, whose digits stretch on into infinity. Using 10101 Software iPi, mathematicians and other Pi enthusiasts can calculate the digits of Pi out to a lengthy number of decimal places. To prevent iPi users from having to start from scratch every time they open the program, iPi allows users to save an in-progress calculation as a PI file. They can load that PI file to quickly pick up where they left off previously.
10101 Software iPi 1 Icon
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DeveloperNeng-Fa Zhou and Håkan Kjellerstrand
Popularity2.0 | 1 Vote
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In-Depth
.PI File Extension
2 file types use the .pi file extension.
iPi Calculation Data
| Developer | 10101 |
| Popularity |
2.6 | 9 Votes |
What is a PI file?
A PI file is a data file created by iPi, a program that calculates the digits of Pi. It stores the progress of a user's Pi calculation. iPi users can load a PI file to resume the calculation the file describes.
More Information
Pi is a mathematical constant that describes the ratio of a circle's circumference to its diameter. Notably, Pi is a never-ending number, whose digits stretch on into infinity.
Using 10101 Software iPi, mathematicians and other Pi enthusiasts can calculate the digits of Pi out to a lengthy number of decimal places. To prevent iPi users from having to start from scratch every time they open the program, iPi allows users to save an in-progress calculation as a PI file. They can load that PI file to quickly pick up where they left off previously.
How to open a PI file
You can open a PI file with 10101 Software iPi. Unfortunately, however, iPi is discontinued. Therefore, if you do not already have access to iPi, you likely will not be able to open your PI file.
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Programs that open PI files
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Windows
10101 Software iPi
—
Discontinued
Free
Mac
10101 Software iPi
—
Discontinued
Free
Category: Data Files
Updated: June 15, 2023
Picat Source Code
| Developer | Neng-Fa Zhou and Håkan Kjellerstrand |
| Popularity |
2.0 | 1 Vote |
A PI file may also be a source code file written in Picat, a logic-based, multi-paradigm programming language . It contains Picat predicates, functions , rules, and data definitions used to create programs for tasks such as optimization, planning, and data processing.
More Information
Picat combines features of logic, functional, and scripting languages. Developers often use it to build applications like scheduling systems that assign tasks, meetings, or jobs to specific time slots while ensuring no two tasks overlap.
Researchers, educators, and developers in fields such as artificial intelligence, operations research, and computational logic are the primary users of PI files. They may execute them directly in the Picat interpreter or compile them into modules that other Picat scripts can import.
How to open a PI file
You can open PI files with any text editor, such as Microsoft Visual Studio Code , Microsoft Notepad , or Apple TextEdit . You can also run PI files using the Picat command-line tool or in development environments that support Picat syntax.
Programs that open PI files
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Platform
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Microsoft Visual Studio Code
Free
Any text editor
Windows
Picat
Free
Microsoft Notepad
Included with OS
Mac
Apple TextEdit
Included with OS
Linux
Picat
Free
gedit
Free
Category: Developer Files
Updated: October 20, 2025