The best replacement for mstsc is vnc.

The best alternatives to mstsc are rated as following:
★★★★★  vnc
★★  rdp

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Speaking about mstsc, one probably shouldn't forget about username and password.

Other search terms related to mstsc and their ratings are:

★★★★★ username and password
You have in mind a companion for mstsc and it is not yet here? Propose!

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