Oh, wow, thanks Josh! That got things rolling a bit, indeed, changing ';' to a ':' helped (I verified before that the bootstrap.jar is in the right place and does contain the needed class) -- so this is again a stupid Unix-vs.-Windows deal? (';' being the Windows separator)

Now I get the following error:

java.lang.NoClassDefFoundError: org/apache/tomcat/util/log/SystemLogHandler
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Class.java:2413)
    at java.lang.Class.getConstructor0(Class.java:2723)
    at java.lang.Class.newInstance0(Class.java:345)
    at java.lang.Class.newInstance(Class.java:327)
    at org.apache.catalina.startup.Bootstrap.init(Bootstrap.java:219)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:391)
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.log.SystemLogHandler
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
    ... 7 more