ToDo manager with dependencies and events

Question

I am looking for a ToDo list application.

Functional properties

Required

• some descriptive text per item
• zero to n other ToDo items the current item depends on
• state (open/done/disabled (while dependencies are not yet marked as done)) for each item
• optionally, a date at which the ToDo item is automatically marked as done

Preferred

• possibly allows to sort items by a user-assigned priority
• stores dates at which items were marked as done
• synchronization between different machines within LAN (i.e. not via a 3rd-party server on the web)

Non-functional properties

Required

• runs on MS Windows 7 and above
• free of charge
• stores its data locally (i.e. does not require accessing any cloud)
• a somewhat usable, point-and-click-based way to see and edit which items are open, and which items depend on which other items

Preferred

• desktop application
• open source
• additional Android client with some synchronization capability (if possible, within LAN rather than going via an account somewhere on the web)
• also runnable on Linux or with a compatible Linux equivalent
• reasonably light-weight

Undesirable, but accepted in absence of more suitable solutions

• rather than a desktop application, runs on/creates its own server and can locally be accessed from within the browser

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• Todo application for web or Linux machine - Primarily looking for Linux application, no requirement of dependencies.

Ruled out Candidates

• Task Coach - Does not support automatical closing of ToDo items by date.
• Todoist - Cloud-based.
• Wunderlist - Cloud-based.
• Wieldy - Does not allow for dependencies between tasks.

Answer 1

How about ToDoList? I find it to be quite powerful and although it does not cover everything you need, a good chunk of it is there:

• some descriptive text per item - check
• zero to n other ToDo items the current item depends on - check
• state (open/done/disabled (while dependencies are not yet marked as done)) - open/done states - check
• for each item optionally, a date at which the ToDo item is automatically marked as done - not sure
• allows to sort items by a user-assigned priority - check
• stores dates at which items were marked as done - not sure
• synchronization between different machines within LAN (i.e. not via a 3rd-party server on the web) - should also be a check
• runs on MS Windows 7 and above - check
• free of charge - check
• stores its data locally (i.e. does not require accessing any cloud) - check
• a somewhat usable, point-and-click-based way to see and edit which items are open, and which items depend on which other items - check
• desktop application - check
• open source - check
• additional Android client with some synchronization capability (if possible, within LAN rather than going via an account somewhere on the web) - no
• also runnable on Linux or with a compatible Linux equivalent - I think it is a check as well
• reasonably light-weight - check

Maybe worth a look.

Answer 2

The Task and To Do areas of Borg Calendar could work. It can be configured to open to the Task manager (rather than the default Calendar) in the program options, and should handle almost all of OP's requirements:

Functional properties

Required

• some descriptive text per item
• zero to n other ToDo items the current item depends on
• state (open/done/disabled (while dependencies are not yet marked as done)) for each item
• NOT SURE | optionally, a date at which the ToDo item is automatically marked as done

Preferred

• possibly allows to sort items by a user-assigned priority
• stores dates at which items were marked as done
• | DON'T THINK SO: MIGHT BE DONE USING OTHER TOOLS:¹ synchronization between different machines within LAN (i.e. not via a 3rd-party server on the web)

^{¹ Maybe rsync or something? I have used BORG with its data on e.g. Dropbox and that worked fine, but that's not what OP is after here.}

Non-functional properties

Required

• runs on MS Windows 7 and above
• free of charge
• stores its data locally (i.e. does not require accessing any cloud)
• a somewhat usable, point-and-click-based way to see and edit which items are open, and which items depend on which other items | IF I'VE UNDERSTOOD OP CORRECTLY! Would need to check this one.

Preferred

• desktop application
• open source
• additional Android client with some synchronization capability (if possible, within LAN rather than going via an account somewhere on the web)
• also runnable on Linux or with a compatible Linux equivalent
• reasonably light-weight

Screen shots

Task Tree:

Task pane:

There is good guidance given in the bundled Help file on using these elements of the app. I have run BORG successfully on each of Windows 7, Ubuntu (18.04 LTS), and Mac OSX (Mojave).