On an adjacent note, the work being done/posted by Collabora motivated me to try to get Mesa + Gallium soft pipe working with emscripten. Here is a demo of the classic glxgears: https://martinmullins.github.io/mesa-softpipe-emscripten/
I had some success last year integrating tesseract OCR and OpenCV with Tabula (compiled to javascript). The purpose was to build a Google Docs pdf table import addon without requiring a backend. Happy to get in touch to figure out how I could contribute the work back to Tabula (if that makes sense).
I haven't seen anything better. It started as a PoC and I decided not to include table detection on the page and require the user to draw box around the table.
I use Tabula under the hood for the cell/row detection and it is really good given the correct mode is selected for the type of table. The modes are stream (find cells by spacing) or lattice (find cells by ruling lines).
