Yes, it allows but it's not free, you need to invest additional amount for the license.
There is an Autonomy Idol tool in SP2010 and 2007 but much like any other enterprise search it will cost a lot for both licenses and hardware requirements.
I have heard of people using ElasticSearch to crawl SharePoint but there will be a steep learning curve to this and you probably will need to have dev skills to write your own connector (or buy one but I'm not sure if they are commercially available). Also this is probably more useful with larger volumes.
You could use lucene directly in combo with tika but again if you have no experience with these technologies it will take a while for you to figure out.
Not trying to change your mind here but SharePoint 2013 search (you don't mention the version you are using) is actually pretty good. So if you are using 2013 you might want to consider getting a SP consultant for a few days as in the long run it will be cheaper than investing in and maintaining new search tech.
Source of the above:
Is there a 3rd party tool that replaces the built in search functionality for documents?