Introduction
The todo.txt format is a simple set of rules that make todo.txt both human and machine-readable. The format supports priorities, creation and completion datesWhen an Event happened, or an Attrribute was true., projects and contexts. That’s all you need to be productive.
http://todotxt.org/
The advantage this offers to genealogists is that a list that conforms to the “rules” is in a plain text file and can therefore be easily moved between PC and Smartphone/Tablet etc. It is probably the nearest you will get to an “application independent” to-do list. Any application (such as MS Notepad) that can handle a text file will do.
The “rules”
The Rules are best illustrated by an example of a file that conforms to those rules. Note that it is “one line per task”.
(A) 2019-02-28 Review +BeaumontParishRecords CarlisleRecordOffice due:2019-03-13
(B) Review +AustralianMilitaryRecords @Ancestry due:2019-04-25
x (A) 2018-12-28 2018-11-30 Renew @FMP subscription due:2018-12-31
The syntax is straight forward:
- (A), (B), etc at the start of the line – Priority and the primary sort
- x at the start of the line indicates the task is done – so will sort to the end
- The Date following the Priority is the Date the task was entered and is optional, unless
- A Done Date is entered in which case there are two dates after the priority: Done, then Entered – this means done tasks get sorted by date done
- Anywhere within the task description +Label indicates a “Project”
- Anywhere within the task description @Label indicates a “Context” (where it is to be done)
- You can have multiple projects and contexts
- Additional data can be handled through Key:Value pairs (such as the due dates above)
Applications
Any application capable of handling plain text will work: Windows Notepad, Ubuntu Leafpad, even a ƒh Note!
There is actually no reason not to keep your list in a ƒh Shared Note. However the shared note cannot (at the moment) be read by another Todo.txt compatible application – and ƒh shared notesFamily Historian version 6 and below supports two types of Notes: Local notes (associated with a single person, record, or fact); and Shared Notes or Note Records, that can be linked to multiple records and/or facts. Version 7 introduced Research can’t line sort.
It is helpful if the text editor can “sort by line” (the above examples can’t). Any “program editor” is likely to be able to do this. For instance Notepad++ can do this. Notepad++ is primarily a Windows program, but works on Linux under WineWine is a free and open-source compatibility layer that allows computer programs developed for Microsoft Windows to run on Unix-like operating systems. https://www.winehq.org/ (like ƒh. Note that through Settings > Shortcut Mapper a short cut key combination can be set up to do Edit > Line Operations > Sort Lines Lexiographically Ascending.

On the todotxt.org home page there are a number of applications listed that give enhanced functionality for todo.txt files. This may include input forms, filters, and advanced search and advanced sort. These work on a wide variety of platforms either as stand alone programs or as add-ins to other programs (mainly email/calendaring programs, not ƒh). Some will work with cloud based storage such as Dropbox.
Example Screenshots:


Alternative
If a one line per task approach is too restrictive, an alternative is to use SimpleNote which can be used to hold a narrative against each task.