user26889: You start by moving the knight's pawn on either side to b3 or g3. Then you do the same on the other side. Ideally, you fianchetto the bishops into both triangle pawn formations.
 [FEN ""]

1. b3 null 2. g3 null 3. Bb2 null 4. Bg2

I tried to use it as Black, but I am still struggling to make it into a strong defense, as it appears to be rather a powerful offensive opening. This opening seems to be gaining popularity at least for White, but I struggle to find information about it on the Internet.

user26801: 1.b3 is called Larsen's opening, while 1.g3 is Benko's opening. They are examples of openings that are collectively called modern or hypermodern.
If you have doubts about opening names, I think the easiest thing to do is play them on a chess engine. Usually the engine will then tell you what is the corresponding name of the opening.

user26888: 1.b3 is Nimzo-Larsen attack. You can check with Lichess database.

user8860: The setup after b3+Bb2 or g3+Bg2 (or on Black's side b6+Bb7, g6+Bg7)
is called a fianchetto https://en.wikipedia.org/wiki/Fianchetto.
Doing this on both Kingside and Queenside is thus called a "double fianchetto";
I don't think there's a more specific name than that.

user307: This set up is often called "The Hippo", a possible reason is that bishops look like the eyes of a hippopotamus.
For example: Eric Rosen: Don't Mess With The Hippo

26889: <p>You start by moving the knight's pawn on either side to b3 or g3. Then you do the same on the other side. Ideally, you fianchetto the bishops into both triangle pawn formations.</p>
<pre><code> [FEN &quot;&quot;]

1. b3 null 2. g3 null 3. Bb2 null 4. Bg2
</code></pre>
<p>I tried to use it as Black, but I am still struggling to make it into a strong defense, as it appears to be rather a powerful offensive opening. This opening seems to be gaining popularity at least for White, but I struggle to find information about it on the Internet.</p>
 26801: <p>1.b3 is called Larsen's opening, while 1.g3 is Benko's opening. They are examples of openings that are collectively called modern or hypermodern.</p>
<p>If you have doubts about opening names, I think the easiest thing to do is play them on a chess engine. Usually the engine will then tell you what is the corresponding name of the opening.</p>
 26888: <p>1.b3 is Nimzo-Larsen attack. You can check with Lichess database.</p>
 8860: <p>The setup after b3+Bb2 or g3+Bg2 (or on Black's side b6+Bb7, g6+Bg7)
is called a fianchetto <a href="https://en.wikipedia.org/wiki/Fianchetto" rel="noreferrer">https://en.wikipedia.org/wiki/Fianchetto</a>.
Doing this on both Kingside and Queenside is thus called a &quot;double fianchetto&quot;;
I don't think there's a more specific name than that.</p>
 307: <p>This set up is often called &quot;The Hippo&quot;, a possible reason is that bishops look like the eyes of a hippopotamus.</p>
<p>For example: <a href="https://www.youtube.com/watch?v=pdAthyBbN7c" rel="nofollow noreferrer">Eric Rosen: Don't Mess With The Hippo</a></p>
