How relevant is the old RFS 5 (Development on Handhelds, <a href="http:&#x2F;&#x2F;old.ycombinator.com&#x2F;rfs5.html" rel="nofollow">http:&#x2F;&#x2F;old.ycombinator.com&#x2F;rfs5.html</a>) today compared to 2009 when it was published?