Calligra Sheets (formerly KSpread and Calligra Tables) is a free software spreadsheet application that is part of Calligra Suite, an integrated graphic art and office suite developed by KDE.Among Sheets’ features are multiple sheets per document, assorted formatting possibilities, support for more than 300 built-in functions, templates, chart, spell-check, hyperlinks, data sorting and scripting with Python, Ruby and JavaScript.Sheets’ native file format has been OpenDocument since version two and previously used its own XML format, compressed with ZIP.