Presenting tuisheet: A love letter to VisiCalc and Lotus 1-2-3.

The motive was to code a programme inspired by VisiCalc and Lotus 1-2-3 interface, running on terminal, but fully compatible with the current universal standard of OpenXML (xlsx files for spreadsheets). Coded in Go lang; apart from my being more familiar with this programming language, it helps making a single executable, low on resources. Also, I like Go's compiler ability to cross compile to many platforms and OSes (which I personally often meet through my daily job). By the way, tuisheet is much more thoroughly tested and used on Linux than on Windows (or Solaris, AIX, BSD).

Mostly vibe coded. Yet with no subscription available, I used a variety of platforms and LLMs to reach a respectful stage to publish it. Started with questions on LLM web sites, then saw an advertisment for Codex with ChatGPT which I used a bit; but free tokens ran out quickly. Moved to OpenCode agent with which I went all along, changing LLMs whenever they stopped being available on the platform (Deepseek free, 0x Alpha, Muse Spark Free). A happy journey of acquittance with LLMs and agents. I can't tell of the effect of LLM switching on the code; I tried to cleanup and optimize, either by my actions or by prompts. Nevertheless the programme is stable and fast for my daily usage, having completely replaced LibreOffice or Excel.

Quick info:

• F1 key shows help.

• / (slash) presents menu. You can navigate either by pressing the capital letter of each option (usually the first letter of its name but not always) or by arrow keys.
  For example, to open a file, the key sequence is: / F R
  To quit, / Q

• Mouse can be used to click to cells. Right click is available in cells, rows, columns and sheets/tabs bar.

Screenshots:

Formulas:

Undo history:

Search results:

File selector to load file:

Perspective view:

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Enjoy! Regarding your precious xlsx files, I quote from licence,

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.