Engram-es optimized keyboard layout for Spanish

Engram-es is a keyboard layout optimized for comfortable and efficient touch typing in Spanish created by Arno Klein as part of a family of Engram layouts (GitHub).

A manuscript has been accepted for publication in the International Journal of Human-Computer Interaction that describes the Engram approach to optimizing keyboard layouts for different languages. The approach is based on language-dependent n-gram frequencies and language-independent typing preferences, using multi-objective optimization informed by crowdsourced typing data. Letters are optimally arranged according to ergonomics factors that promote reduction of lateral finger movements and more efficient typing of high-frequency letter pairs. The most common punctuation marks are logically grouped together in the middle columns and numbers are paired with mathematical and logic symbols.

      [ | = ~ +   <  >   ^ & % * ] \
      ( 1 2 3 4   5  6   7 8 9 0 ) /

        Z H O X  .:  "'  M D B J W -_ #@
        P I E A  ,;  ☆   T S N R K
        F Y Q U  ¿¡  ?!  C L V G
        
☆ + aeiouAEIOU = áéíóúÁÉÍÓÚ (acute accent)
☆ + nN = ñÑ
☆ + cC = çÇ
☆ + Shift         + [letter] = [letter] with a diaresis/umlaut: ü
☆         + AltGr + [letter] = [letter] with a grave accent: è
☆ + Shift + AltGr + [letter] = [letter] with a circumflex: â
AltGr + ( = { (open curly brace)
AltGr + ) = } (close curly brace)
AltGr + 5 = « (open quote/comillas) 
AltGr + 6 = » (close quote/comillas)
AltGr + - = — (em dash)
AltGr + ' = ` (back tick)
AltGr + . = • (middle dot, or "interpunct")
AltGr + s = $ (dollar currency)
AltGr + e = € (euro currency)
AltGr + l = £ (pound currency)

Layout (default, Shift, and AltGr layers)