Novell's single sign on product will do exactly what you are asking for. Currently their product snaps into e-directory which can run on all platforms that you mentioned (Windows, Linux, Solaris and Netware). Take a look at it.. Novell has really gone out of their way to support multiple platforms. As a bonus they are one of the only company's embracing the open source community. Some of their products are developed for Apache and Jakarta Tomcat. They are also actively contributing code to both of those projects.
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For those of you wondering... It does still exist... Screw the 12 year old I wish I could send something back 10 min ago!!!
Novell's single sign on product will do exactly what you are asking for. Currently their product snaps into e-directory which can run on all platforms that you mentioned (Windows, Linux, Solaris and Netware). Take a look at it.. Novell has really gone out of their way to support multiple platforms. As a bonus they are one of the only company's embracing the open source community. Some of their products are developed for Apache and Jakarta Tomcat. They are also actively contributing code to both of those projects.