The first OSGi book Programming Open Service Gateways with Java Embedded Server(TM) Technology was written in year 2000, the second edition in 2001. The book was written / sponsored by ...Sun Microsystems. At that time there was also a commercial OSGi server available (Sun again): Java Embedded Server (JES) - I almost used JES in an embedded Java project. JES worked really well, but was discontinued. ...a few years before the OSGi hype...
[I even found this book on my bookshelf - didn't actually noticed that it is so old...]