Because you prefer making your business sustainable now (even if it's just $100 per month) than a possible 1 billion dollar valuation down the uncertain future.

Spreadsheet software library Do you find existing libraries hard to use? Shouldn't the code be as intuitive as using the Excel software? Click here to find out more about SpreadsheetLight

Programming guide on Open XML spreadsheets Because you're hardcore and want to write the code from scratch yourself. Click here to find out more about Spreadsheet Open XML From Scratch

I write about maths, programming, entrepreneurship and business stuff. I also make videos.

Read these first.

1. Cartesian coordinates and transformation matrices
2. Percentage calculation with negative numbers
3. Reverse engineering Bezier curves
4. Image rotation with bilinear interpolation
5. Custom column widths in Excel Open XML

Any code published on this blog, unless otherwise stated (say it's by another person, or that I'm selling my code), is licensed under the MIT License.