My day job is an ICT Systems Technician an in a medium-sized school, and having not long left full-time education myself I have come across a lot of free legitimate software for schools and students. These will be some of my favourites.
They will most likely need a school-related email to be able to use and may only be available for older age schools. They may also have other eligibility requirements.
This will not induce discounts.

Github education Pack
Link

This is a large pack of software aimed at getting young people to code in a more complex language than drag and drop. The pack includes text editors, server hosting, free domains and much more that could be its own post by itself.

AutoDesk Suite
Link

This is the whole Autodesk suite of programs for free; students, teachers & schools with up to 1200 seats per license. That is several million in free software, that is if your pcs can run it.

Unity Game Engine. 
Link

Although I prefer UE4 Myself, that is free across the board so not suitable for this list. There will be a comparison here. Anyhow, Unity offers free education licenses to education establishments, which I believe is slightly different than their personal licenses, is easier to distribute across a network and means you do not have to pay the license fee if your school has a revenue of over 100K A year.
Students/teachers are free to download the personal version anyway.

NB; They are various other programs out there and will be added in the future, some programs such as Microsoft dream spark are currently down and will not be added until they come back up.