[This SeaMonkey extension restores old-style Search sidebar tab, complete with search results and multi-engine search.

Screenshot:

Features:

• Replaces default bare-bones Search tab on SeaMonkey;
• When a search is performed, search results will be gathered and displayed in the sidebar;
• Basic mode provides a search field, search engine selection dropdown and results list. Advanced mode drops search engine selection in favor of a list containing all search engines which can be checked on or off individually;
• In Advanced mode, categories are used to filter search engines. Additionally, checked engines are remembered for each category and for All Engines mode.
• If a search is performed with more than one engine checked, a Search Results tab opens. It contains a large table of results and a dropdown to view each results page individually;
• Search results can be blacklisted by page URL and domain;
• Search queues can be bookmarked;
• "Previous" and "Next" buttons at the bottom of the sidebar tab provide means to navigate results even with the actual results tab closed;
• The original implementation only gathered results when a search was performed using the Search button, but not when just opening a page with results. Unlike the original implementation, this one detects any performed search, be it opening a bookmarked page with results, re-opening a closed tab with results etc.

Limitations:

• "Search rules", the rules by which the extension determines how to retrieve results from a loaded web page, must be entered manually for each engine. Currently no default rules are provided;
• Search query can only be remembered if the search was performed through sidebar. Otherwise the results will be there, but not the query, since there aren't any ways to retrieve the query from an arbitrary search as for now;
• The results are only refreshed when an actual page is loading. If the engine retrieves its results through an AJAX request (without page refreshing), you'll have to refresh the page manually.

Some examples of search rules:

Google:

Option	Value
URL filter	https?://www.google.com/search
Container	.g .rc
Title	.r
Link	.r
Description	.st
Preview	img
Previous page	#pnprev
Next page	#pnnext

Yahoo:

Option	Value
URL filter	https://(\w+.)?yahoo.com/search
Container	.dd.algo
Title	a
Link	a
Description	p
Preview
Previous page	.prev
Next page	.next

DuckDuckGo:

Option	Value
URL filter	https?://duckduckgo.com/?q=
Container	.result__body
Title	.result__a
Link	.result__a
Description	.result__snippet
Preview
Previous page
Next page

YouTube:

Option	Value
URL filter	https?://www.youtube.com/results
Container	.item-section > li div.yt-lockup
Title	.yt-uix-tile-link
Link	.yt-uix-tile-link
Description	.yt-lockup-description
Preview	.yt-thumb
Previous page	.yt-uix-button[data-link-type="prev"]
Next page	.yt-uix-button[data-link-type="next"]

Wikipedia

Option	Value
URL filter	https?://en.wikipedia.org/w/index.php
Container	.mw-search-results > li
Title	.mw-search-result-heading
Link	.mw-search-result-heading
Description	.searchresult
Preview
Previous page	.mw-prevlink
Next page	.mw-nextlink
Wikipedia engine is a bit special. When a search is performed and an article
exists of the same name as the search query, the article is loaded directly,
bypassing the search results. In this case search results will not be shown.
In multi-engine search mode, a link to the resulting page will be added to the
table instead.