aliciagh

Easily search through all blogs into your WordPress MU posts by post title, post content or post author. 
WPMU Global Search can manage multiple search forms. Currently in the following languages:
<ul>
<li>English</li>
<li>Spanish (es_ES)</li>
</ul>
If you have created your own language pack, or have an update of an existing one, you can send <a href="https://codex.wordpress.org/Translating_WordPress" rel="nofollow ugc">gettext .po and .mo files</a> to me so that I can bundle it into WPMU Global Search.

WPMU Global Search

Adds the ability to search through blogs into your WordPress MU installation.

Anton Paramonov

Pretty simple plugin for disable:
<ul>
<li>the XML-RPC on a WordPress site running 3.5 or above</li>
<li>new emoji functionality in WordPress 4.2</li>
<li>Posts and Comments general feeds</li>
</ul>
And remove:
<ul>
<li>WordPress genarator meta tag from HTML source page</li>
<li>link to wlwmanifest file from HTML source page (Windows Live Writer)</li>
<li>link to RSD EditURI from HTML source page</li>
<li>X-Pingback from HTTP headers and pingback_url in HTML source page</li>
<li>shortlink from HTTP headers and HTML source page</li>
</ul>
Translated on English, Russian and Ukraine languages.

YaBlog

Allows administrators to globally disable XML-RPC, new emoji functionality in WordPress 4.2, wp generator, wlwmanifest, RSD EditURI and rss/feeds on t …

WPMU Global Search vs YaBlog