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Proton
Empowering you to choose a better internet where privacy is the default. Protect yourself online with Proton Mail, Proton VPN, Proton Calendar, Proton Drive. Proton Pass and SimpleLogin.
Proton Mail is the world's largest secure email provider. Swiss, end-to-end encrypted, private, and free.
Proton VPN is the world’s only open-source, publicly audited, unlimited and free VPN. Swiss-based, no-ads, and no-logs.
Proton Calendar is the world's first end-to-end encrypted calendar that allows you to keep your life private.
Proton Drive is a free end-to-end encrypted cloud storage that allows you to securely backup and share your files. It's open source, publicly audited, and Swiss-based.
Proton Pass Proton Pass is a free and open-source password manager which brings a higher level of security with rigorous end-to-end encryption of all data (including usernames, URLs, notes, and more) and email alias support.
SimpleLogin lets you send and receive emails anonymously via easily-generated unique email aliases.
Not really. Them not using ads means they can't make money that way, so the only way they can make money is through subscriptions. Even a not for profit needs to pay people and pay for overhead. If everybody used the free service they would go under over night. As long as they continue to respect privacy they have every right to have these pop-ups. Especially since they don't force you to subscribe.
Quick note, Proton AG itself (the for profit company) still owns, operates and develops the Proton services as we know. The only difference with the non-profit structure is that Proton AG is owned by the proton foundation. Which basically is a protection against aggressive takeovers and the enshittification that would follow. Also, tax advantages, probably.
From what I understand since the proton nonprofit is established in Switzerland, it's more restrictive than the USA