Both apps provide a way to effectively write code (script) inside Jira. ScriptRunner additionally offers a large variety of built-in functionalities accessible without the need to code and unlimited scripting possibilities using Groovy. Scripting in Power Scripts is done in the SIL language, which is easier to learn, stable across Jira versions but its limited in functionality.
ScriptRunner for Jira
ScriptRunner for Jira was the first add-on in the marketplace to allow access to the Jira API via its powerful Script Console. Sold by Adaptavist - the largest Atlassian services provider worldwide, the app has over 24k active downloads and over 400 reviews, with an overall rating of four stars.
ScriptRunner offers a staggering amount of functionalities including but not limited to: complex workflow automations and customisations; 3rd party tool integration; modifying Jira's user interface; considerable extensions of Jira's native JQL; integration of external SQL databases; making fields, forms and issues look, feel and behave according to custom logic; creating custom fields that show calculated data from other issues, etc.
You don’t need to write code to access many of these features. ScriptRunner has a vast array of no-code functionalities based on the most common use-cases. However, to implement very complex automations or customisations, you have to run Groovy scripts inside ScriptRunner. As Groovy code is backed up by the Jira API directly, ScriptRunner basically gives you direct and unlimited access over Jira.
ScriptRunner has a very large and active user base, so you will find a lot of help and ideas for your scripts under the ScriptRunner tag in the Atlassian Community or in the Adaptavist Library - a free resource containing a lot of ready-made scripts you can just copy and use. Also, Groovy is very similar to Java, the most popular programming language, so someone with Java knowledge will have no problem writing Groovy.
Power Scripts for Jira
Power Scripts for Jira is sold by Atlassian top vendor CPrime, has over 1,837 active downloads and a rating of 4 stars from 118 reviewers.
Power Scripts allows workflow customisation, integrations with internal/external databases, system updates and more. It does not provide no-code functionalities.
For scripting, you would use the Simple Issue Language 4.0, aka SIL. SIL is built-it into Power Scripts and it makes things simpler for admins who don’t want to code Java or Groovy. While it is another language you’d have to learn, it is a very simple one that doesn’t require much anterior coding knowledge.
While Java and Groovy are backed up by the Jira API directly, SIL doesn’t give you direct access to Jira’s core. If a functionality is not defined in SIL, then you cannot implement it using Power Scripts.