Sedit
Originally created for Spark's predecessor, ARC, Sedit has been the de facto standard for many years, and is Spark's premier map editing program. (Windows)
Just download the archive, extract it to its own directory and run the file sedit.exe - this archive contains everything required to run the program.
Though straightforward to use, Sedit lacks thorough documentation. Thankfully, there are many in the Spark community with years of experience in map-making that are happy to help, including Wave, whose Sedit map-making tutorial can be found here: http://sedit.spark-stuff.net
Happy map making!
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