I was reviewing my time tracking arrangements and thought I would share the results of my search for a better solution. I had specific requirements, so this isn’t for everyone, but I hope it might be useful to some. Results are ordered by my entirely unscientific rating system.

If you know of any I missed, let me know in the comments.

Required for consideration

• Free
• Runs on Linux
• Access to data store (no proprietary web services)
• Easy start/stop of tasks (i.e. don’t have to manually enter start and end times)

Important

• Cross-platform
• Open source
• Work offline
• Manually add/edit time
• Nestable items
• Export reports of total time spent on an item with breakdowns

Desired

• Stop tracking activity when computer is idle or off
• Reminder of current activity
• Nice graphical reports
• Tagging
• Collaboration

Kimai

Pros:

• Open source
• Slick interface
• Easily manually add or edit time entries
• Tasks are assigned to projects, which are assigned to customers — this is as good as nesting, for me
• Export reports filterable by customer, project, or task to PDF, XLS, CSV, or HTML
• Same task can be tracked against multiple customers — as good as tagging, for my purposes
• Multi-user, web-based
• Freelance/consultant-specific features: rate, expenses, location, and total cost in reports

Cons:

• Can’t work offline if installed on a remote server
• No idle/off detection
• No reminder of current task
• No graphical reporting

Verdict: +8 / -4
Solidly fits my working requirements in a very nice interface, though I’ll have to consider whether I want to use it as a local installation and not enjoy its multi-user capabilities or install it on my server and not have access to it offline.

Project Hamster

Pros:

• Open source
• Easy, intuitive interface
• Manually add/edit time easily
• Nice graphical reports
• Exportable reports
• Configurable idle/off detection
• Configurable reminder of current activity
• Tagging (in repository)

Cons:

• Not very cross-platform — only partial Windows compatibility, main focus is the Gnome desktop environment
• Limited to one level of categories
• Export totals per task only, not category
• No collaborative capabilities

Verdict: +8 / -4
Does most of what I need it to do, and with a pretty good interface to boot.

Rachota

Pros:

• Open source
• Tagging, of a sort (spaces in the category field of a task cause it to be assigned to multiple categories at once)
• Configurable idle/off detection (in development build)
• Decent, filterable reporting
• Exportable reports configurable by time period and filterable by task

Cons:

• Sometimes confusing interface
• Can’t easily add/edit time (coming in next version?)
• Only one level of categories
• Idle detection doesn’t really work, off detection doesn’t work all the time
• No reminder of current task
• No collaborative capabilities
• Doesn’t exit gracefully when the computer shuts down

Verdict: +5 / -7
The interface isn’t great, but the real killer with this one is its inability to manually add or edit time. Hopefully this will improve as development progresses.

TimeSlotTracker

Pros:

• Open source
• Manually add/edit time
• Nestable tasks
• Export report of total time spent per task, filterable by date and parent task, to HTML, TXT, and CSV
• Export customizable via XSLT

Cons:

• No graphical reports
• Clutters up home directory with non-standard files
• Default export templates are unappealing
• Configurable current task reminder which sadly doesn’t seem to work
• No idle/off detection
• No tagging
• No collaborative capabilties

Verdict: +5 / -7
A simple cross-platform, open source time-tracker with limited export options and reporting; its inability to nest items and poor reporting won’t work for me.

Klok

Pros:

• Nice interface
• Great calendar view to easily add/edit/visualize time
• Pie chart reports with easy drill-down
• Nestable tasks

Cons:

• Bugs (activity is sometimes saved with zero length)
• Can’t export reports, only weekly or monthly time sheets (not overall project totals)
• Not open source? Can’t find license or source code
• No idle/off detection
• No reminder of current task
• No tagging
• No collaborative capabilities (apparently coming in next version)

Verdict: +4 / -7
Despite the pleasantly useful interface, the shortcomings (namely the occasional bug and lack of report exporting) mean it doesn’t fulfil my needs. Those who don’t need the exporting or other features may enjoy it, however.

Time-Tracking-Tool

Pros:

• Tasks can be nested
• Report on total time spent filterable by task and time period
• Save application data for reopening elsewhere
• Edit recorded time for a task

Cons:

• Not open source? Can’t find license or source code
• Reports overly simplistic, don’t handle subtasks well
• Can’t export reports
• Can’t view or edit start and end times of activity
• No tagging
• No idle/off detection
• No reminder of current task
• No collaborative capabilities

Verdict: +4 / -8
Perhaps useful for those who like simplicity, but the uncertainty around its license and its omissions make it a non-starter for me.

Baralga

Pros:

• Open source
• Save application data for reopening elsewhere
• Manually add/edit time

Cons:

• Interface clunky in places
• Can’t nest tasks/projects
• Can’t export reports, only an Excel spreadsheet or CSV file containing time spent per project per day
• Only one, limited visual report
• No idle/off detection
• No reminder of current task
• No tagging
• No collaborative capabilties

Verdict: +3 / -8
A simple cross-platform, open source time-tracker with limited export options and reporting; its inability to nest items and poor reporting won’t work for me.

Other options

These are a couple that piqued my interest but weren’t worth trying out because of a lack of cross-platform compatibility.
Windows-only:

• ToDoList
• Grindestone2