Download of Spark 2.9.4 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus.
The software lies within Communication Tools, more precisely Texting & Video calls. The following versions: 2.6, 2.5 and 2.1 are the most frequently downloaded ones by the program users. The actual developer of this free software for Mac is Jive Software. Spark_2_6_3.dmg is the frequent file name to indicate this application's installer.
From the developer:
Spark is an Open Source, cross-platform IM client optimized for businesses and organizations. It features built-in support for group chat, telephony integration, and strong security. It also offers a great end-user experience with features like in-line spell checking, group chat room bookmarks, and tabbed conversations.
Combined with the Openfire server, Spark is the easiest and best alternative to using un-secure public IM networks.
You may want to check out more Mac applications, such as Spark Dev, Spark Vintage Drum Machines or Spark ToDo, which might be similar to Spark.