The header of psyco.sourceforge.net states:
High-level languages need not be slower than low-level ones.
Why use need not instead of do not need? What does it mean? Also, why no to before be?
There are two verbs need, which mean the same thing but use different constructions:
This need is a modal verb: it always requires an infinitive without to; it doesn't have do-support in questions and negative sentences; and the third person singular (he/she/it) doesn't have -s. This is the need in your example.
It is slightly old fashioned. Except in negative sentences and questions, I don't think you will see it much in modern writing, except in certain fixed expressions, such as if need be ("if necessary").
This is the more common need, a regular verb (no modal). If it is used with another verb, the infinitive with to is used. It always has do-support. It can be used without another verb, with a direct object (you need him).
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