Open Source Scanning Software
Scanning paper is supposed to free you from it, but bundled scanner software often does the opposite - pushing your documents through a vendor account, an OCR cloud, or a format that pins the result to one app, just to digitize a stack of receipts. The open source tools here capture, clean up, and OCR scans into ordinary PDFs and images on your own machine, so turning paper into files doesn't route your records through anyone else's service.
NAPS2
Scan documents to PDF, TIFF, JPEG, or PNG from any WIA, TWAIN, SANE, or ESCL scanner
Mini QR
Design styled QR codes and scan them, with batch export and PWA install
scanservjs
Web UI for SANE scanners that shares any scanner on your network, no vendor drivers needed
ScanTailor Advanced
Interactive cleanup tool that turns raw scanned pages into clean output for print, PDF, or DjVu