SQL Server is a fork of Sybase. Not a MS invention.
Active Directory is probably based on someone's LDAP server, though I don't know for sure.
.NET is a copy of Java
NT kernel is good, thank Digital/Dave Cutler for that.
> .NET is a copy of Java
A copy which has had value types (Java's ongoing Project Valhalla) from the start, and reified generics for as long as it had generics. They're quite different once you take a deeper look.
NT, SQL, AD is good. It's the schizophrenic management in the last 20 years that has messed it up.
> SQL Server is a fork of Sybase. Not a MS invention.
It's long-since been rewritten. Pre-SQL Server 2000 it was garbage, but it's been improved significantly since then. I'd still use alternatives given the choice, but it's a solid DB.
>Active Directory is probably based on someone's LDAP server, though I don't know for sure.
So you don't know. It was written in house, using a bunch of standardized protocols (LDAP, X.500, kerberos), though with proprietary extensions (GPOs, etc).
> .NET is a copy of Java
That's a gross oversimplification. It's arguably a rip-off after MS tried to sabotage java, but it's their own implementation.
> NT kernel is good, thank Digital/Dave Cutler for that.
Yes, MS hired an experienced OS person for it. Probably one of the best things they ever did.
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I'm not saying MS deserves kudos or the benefit of the doubt, but they can put out good software, and these are all mission-critical examples of what they have to (having AD go down would bring a whole corporation to a halt). The problem is that with almost everything else, MS has the incentive and capability to ruin. And ruin they do...