How can i change and customize the special characters on my keyboard?

Solution 1:

You might want to try just defining ¬ as λ in system prefs/language & text/text/symbol and text substitutions. Normally you need to type a space or another character to get the switch, and there may be some apps it does not work in (Pages and Word have their own symbol and text substitution settings).

Solution 2:

Is there a way to do this without creating a new keyboard layout?

You can do it by defining Service:

1. Run Automator
2. Choose a type for your document: Service
3. Check Text from Library on the left
4. Double click Get Specified Text
5. On the right check Output replaces selected text

6. Paste your character into text editor window of "Get Specified Text"

7. Run System Preferences and choose Keyboard -> Keyboard Shortcuts

8. Choose Services
9. Find your brand new service and assign it a shortcut

Or with key bindings.

Solution 3:

You can create ~/Library/KeyBindings/ and save a property list like this as DefaultKeyBinding.dict:

{
    "~l" = (insertText:, "λ");
}

After reopening applications, ⌥L should insert λ in most text views. It doesn't work in for example Terminal or Xcode though.

Other options:

• Make a custom keyboard layout
• Add characters to the press and hold popovers
• Use TextExpander or a DIY alternative to it