For typing at a keyboard I recommend the rational keyboard layout by Marcin Woliński. While being 100% compatible with standard QWERTY Polish layout (“Polski-programisty”), it additionally utilizes dead keys to provide a vast variety of interpunction and diacritics, resulting in the ability to comfortably input French, German, Italian, etc. texts without switching the keyboard layout. Not only is this layout included in the majority of Linux distributions but also it has been ported to Windows (by me) and is available for download at the webpage linked above.
For visualizing genealogical data in GEDCOM format I recommend my mini-projects: topola-webpack (for generating interactive, self-contained genealogical trees) and ged2html (for generating multi-part, hierarchical yet concise HTML documents, which can be easily printed or exported to PDF).
Links to related pages with some of my contribution (in some cases, from many years ago) are on the right-hand side of this paragraph or below. ⇲