Kactus currently supports macOS 10.9 (or higher).
Download the Kactus.zip, unpack the application and put it wherever you want.
Kactus will create directories to manage the files and data it needs to function. If you manage a network of computers and want to install Kactus, here is more information about how things work.
~/Library/Application Support/Kactus/- this directory contains user-specific data which the application requires to run, and is created on launch if it doesn't exist. Log files are also stored in this location.
Kactus will generate logs as part of its normal usage, to assist with troubleshooting. They are located in the data directory that Kactus uses (see above) under a logs subdirectory, organized by date using the format YYYY-MM-DD.kactus.production.log, where YYYY-MM-DD is the day the log was created.
Problems with installing or updating Kactus are tracked in a separate file which is managed by the updater frameworks used in the app.
~/Library/Caches/io.kactus.KactusClient.ShipIt/ShipIt_stderr.log- this file will contain details about why the installation or update failed - check the end of the file for recent activity.