GSCalc is a full featured spreadsheet with unique capabilities for processing big data sets.
You can edit large CSV files with millions of rows, XLSX files that are automatically split and merged,
build complex data models e.g. with millions of lookup formulas that are opened/updated almost
instantly and clean, transform, publish multigigabyte data sets.

32 million rows x 16,384 columns.
The number of worksheets and subfolders is unlimited. No limit for the file size.
Large text, CSV files exceeding the 32M/16K limits are automatically split into multiple sheets
and saved together in one zip.

Organizing worksheets in a tree form and creating 3D array cell references for
worksheets in a given subfolder (by specifying only the folder path in the reference).

Optimized to process large files. GSCalc easily outperforms other existing spreadsheet solutions
and redefines what the term "large data set" means for desktop software.
→ Performance examples.
GSCalc vs Excel (for data sets only within the 1M Excel limit):
 Loading text files should be around 1020 times (or more) faster in GSCalc.
 Copying/pasting/filling large data blocks should be on average from several times faster in GSCalc. For blocks containing formulas this can increase to tens of times or more.
 Performing VLOOKUP and MATCH for newly pasted/entered data in large data sets can be executed from several times and up (possibly hundreds of times) faster in GSCalc.
 GSCalc workbooks saved in its binary file format are a few times (and up) times smaller than files in the Excel XLSB binary file format and can be accordingly faster.

Pivot table data functions GSCalc vs Excel:
Excel: 11 functions, 1 million rows;
GSCalc: 25 functions, chi2 tests, 32 million rows, full regex filtering.
 Fast pivot tables with up to 32 million rows, builtin reports, many functions and filtering options.
 Monte Carlo Simulations to easily estimate risk in business, costs, future pensions or simply to reversecalculate formulas etc.

Mass modifying/adding/removing parameters/arguments used by functions in large workbooks
without the risk of making mistakes in long formulas.

VLOOKUP, HLOOKUP,
MATCH, UNIQUE,
FILTER functions using fast binary searching
to ensure the best performance for worksheets with millions of rows.
For example, one million vlookup() functions in a table with a few million rows can
be updated almost instantly even on a slow, old pc with 8GB RAM.

No limitations for using cell references to external closed workbooks in all functions
including the INDIRECT() function and functions written and added by users.
Closed workbooks are automatically opened in the background when updating formulas
and can either remain open in the background for best speed or can be automatically
closed to save memory so that only one is loaded at a time.
 Use of regular expressions in the lookup and text functions and in the Find and Replace function.
 The FILTER() function to quickly filter millions of rows (and/or to perform multikey sorting and searches for duplicates).
 Charts easily handling millions of data points with custom vertical and horizontal (grid)lines.
 Fully configurable crosshighlighting to ensure the best screen readability.

No limitations for the number of hyperlinks and its usage. Workbook hyperlinks created instantly by the Copy/Paste commands.
No limitations for conditional formatting  you can instantly create and efficiently use millions of rules.
 Users can specify from 1 to 64 processor cores to be used by GSCalc for calculations.
 Around 450 builtin functions. Users can add their own DLL libraries with new functions or functions replacing the default ones, with the same performance, dynamic array and multicore calculations.
 Each single worksheet window can be split into up to 100 panes (with optionally synchronized rows and/or columns scrolling) to display various regions of that worksheet or other worksheets.

JScript and VBscript scripts making it easy to massmerge tables and records from csv/text/xlsx/xbase/MySQL/SQLite files.

Two optional native file formats: Open Document *.ods spreadsheet format and exceptionally fast and compact binary format which 
thanks to various data patterns analysis  enables you to generate even tens of times smaller files than those saved by other popular spreadsheets.

Loading/editing/saving tables with millions of rows saved as Excel *.xlsx and *.xls workbooks; tables with rows
exceeding the *.xlsx and *.xls row limits are automatically split and saved (or loaded and merged) either as multiple xlsx/xls files or as multiple
worksheets in one workbook.

Loading/editing/saving CSV, text, xls, xlsx, dBase, Clipper, FoxPro, MySQL, SQLite files with up to 32 million rows (and up to 1 million columns for text files);
all existing files are edited inplace, without changing their format or parameters/structure.

Verifying data integrity with SHA256 checksums when switching between file formats.
 Support for JScripts & VBScripts. Organizing scripts hierarchically in trees.
 2D/XY and 3D charts handling millions of data points instantly.
 Saving workbooks to PDF: saving entire workbooks, single worksheets, ranges or single charts to compact PDF files.

Specialized numerical functions: matrix decompositions; linear equation sets with improving
iterations; least squares (weighted, constrained), regression with orthogonal polynomials; time series analysis; minimization;
linear programming, integer programming and quadratic programming.

GSCalc can be installed on any portable storage device and used without performing any registry modifications.
Fully offline  doesn't need internet connection.
Version: 20.7 64bit
File size: 5.72MB
System: 7/8.x/10/11 64bit
Videos created on Intel Core i57500 @3.40GHz / 16GB RAM; CPU benchmark 8K [ vs 60K for Intel Core i913900K ]
Using the FILTER() function to filter 3.3 million rows.
Using a 2.37GB workbook file with i5, 16GB RAM & HDD:
32 million formulas and 300 million random number/text cells.
Creating a script in GSCalc to massimport tables from CSV/text/xBase/xlsx files
Using MonteCarlo simulations to find sets of 100 numbers that add up to a give value.
MonteCarlo simulations in GSCalc to find linear programming solutions.
12 million fast binary VLOOKUP's in GSCalc.