Package: libyear
libyearAsimplemeasure of software dependency freshness. It is asingle numbertelling you how up-to-date your dependencies are.https://libyear.com/How to installpip install libyearUsageA single requirement filelibyear -r requirements.txtA folder with requirement fileslibyear -r requirements/Example outputlibyear -r requirements.txt 
+-------------------------+-----------------+----------------+-----------------+
|         Library         | Current Version | Latest Version | Libyears behind |
+-------------------------+-----------------+----------------+-----------------+
|           pytz          |      2015.2     |     2019.3     |       4.54      |
|         urllib3         |      1.15.1     |     1.25.7     |       3.58      |
|         astroid         |      1.5.3      |     2.3.3      |       2.43      |
|          django         |     1.11.23     |      3.0       |       0.34      |
|      django-celery      |      3.2.1      |     3.3.1      |       2.54      |
|        httpretty        |      0.8.3      |     0.9.7      |       5.31      |
|         Pygments        |       1.6       |     2.5.2      |       6.81      |
|          flake8         |      3.6.0      |     3.7.9      |       1.01      |
|      django-waffle      |      0.14.0     |     0.18.0     |       1.66      |
|    requests_oauthlib    |      0.8.0      |     1.3.0      |       2.72      |
|   django-debug-toolbar  |       1.8       |      2.1       |       2.52      |
|         libsass         |      0.13.3     |     0.19.4     |       2.06      |
|     django-storages     |      1.6.6      |      1.8       |       1.65      |
|      edx-i18n-tools     |      0.4.2      |     0.5.0      |       2.02      |
|           six           |      1.10.0     |     1.13.0     |       4.08      |
|   djangorestframework   |      3.6.3      |     3.11.0     |       2.58      |
|          isort          |      4.2.15     |     4.3.21     |       2.05      |
|         futures         |      2.1.6      |     3.3.0      |       5.5       |
|          Pillow         |      2.7.0      |     6.2.1      |       4.8       |
| edx-django-release-util |      0.3.1      |     0.3.2      |       2.44      |
|      beautifulsoup4     |      4.6.0      |     4.8.1      |       2.42      |
|       mysqlclient       |   1.4.2.post1   |     1.4.6      |       0.77      |
|         newrelic        |    4.14.0.115   |   5.4.0.132    |       0.78      |
|          redis          |      2.10.6     |     3.3.11     |       2.16      |
|         oauthlib        |      2.1.0      |     3.1.0      |       1.21      |
|        django-ses       |      0.7.1      |     0.8.13     |       3.65      |
|           mock          |      1.3.0      |     3.0.5      |       3.79      |
|      django-hamlpy      |      1.1.1      |      1.2       |       1.52      |
|          bottle         |      0.12.9     |    0.12.18     |       4.1       |
|      pylint-django      |      0.7.2      |     2.0.13     |       3.44      |
|       user-agents       |      1.1.0      |      2.0       |       2.13      |
|          jsmin          |      2.2.1      |     2.2.2      |       1.15      |
|         Markdown        |       2.4       |     3.1.1      |       5.26      |
|         gunicorn        |      0.17.4     |     20.0.4     |       6.59      |
|         requests        |      2.18.4     |     2.22.0     |       1.75      |
|          pylint         |      1.7.2      |     2.4.4      |       2.39      |
+-------------------------+-----------------+----------------+-----------------+
Your system is 103.78 libyears behindExample 1For example, a rails 5.0.0 dependency (released June 30, 2016) is roughly 1 libyear behind the 5.1.2 version (released June 26, 2017).Simpler is BetterThere are obviously more nuanced ways to calculate dependency freshness. The advantage of this approach is its simplicity. You will be able to explain this calculation to your colleagues in about 30s.Example 2If your system has two dependencies, the first one year old, the second three, then your system is four libyears out-of-date.A Healthy AppApps below 10 libyears are considered to be healthy apps. We regularly rescue projects that are over 100 libyears behind.Etymology"lib" is short for "library", the most common form of dependency.ReferencesJ. Cox, E. Bouwers, M. van Eekelen and J. Visser, Measuring Dependency Freshness in Software Systems. In Proceedings of the 37th International Conference on Software Engineering (ICSE 2015), May 2015https://ericbouwers.github.io/papers/icse15.pdf