So, to anyone wanting to build the latest version from source, this is what I did. Hopefully this helps anyone looking to do the same.
I'm running Windows 10 64 bit and want the 1.15.2 version, so you're downloads may vary.

I used this video to setup the IDE:

1. Download the Java 8 SDK, I went with jdk-8u251-windows-x64.exe from https://www.oracle.com/java/technologies/javase-jdk8-downloads.html. Install it.
2. Download an IDE. IntelliJ Idea was in the video so I downloaded the community edition from https://www.jetbrains.com/idea/download/#section=windows Install it with defaults. Its gonna ask for restart to register path additions. Restart comp if necessary.
3. Download source from https://github.com/killjoy1221/TabbyChat-2/tree/1.15 and use "Clone or download" button to get the zip. Unzip file into its own directory.
4. Open IntelliJ. Accept defaults. Use the popup menu to Import Project. Navigate to TabbyChat directory and select "build.gradle".
5. Let IntelliJ do its magic. After its done downloading/compiling/setting up, you may want to test it.
6. In the upper right hand corner of IntelliJ, look for a Gradle sidebar, select it, Navigate to TabbyChat > Tasks > fg_runs > genIntellijRuns. Double click, let it run.
7. After its finished, you can run the client by going to upper right hand menu with a dropdown next to the green triangle, open the menu, select Run Client, and it will run Minecraft with user Dev.
8. This next step may be unnecessary. Go back to Gradle sidebar, select it, Navigate to TabbyChat > Tasks > build > jar.  Double click, let it run.
   To get the actual TabbyChat mod jar, just navigate to TabbyChat directory in your system, build folder > libs > TabbyChat-2.4.0-SNAPSHOT.jar

In reply to killjoy1221:

 Man, you're awesome.  Thanks for the tips. That is a lot easier than my overkill IDE route.  I didn't use adoptopenjdk since when I looked at it, in the past it seems to bug out with different versions of gradle.  Figured it would just be easier to use official java.

I like looking at your code though, since it's very readable and easy to follow through the logic.

This is a great chat mod, if you like not updating your Minecraft client for 6 months because Forge takes so long to issue a release.

Really hoping they release a Fabric version for 1.14 so I can go back to using it.  Forge takes so long to release that I gave up and moved on to Rift and then Fabric and I don't use Forge any more.

In reply to killjoy1221:

Yeah, about that, I'd like to build it from source but had some questions.  1)  Does this still require liteloader?  2) I noticed you added Kotlin to the mix, is there anything special that needs to be added to the config for this? 3) Does the mnm library need to be separately downloaded when setting the environment up?

I used to build with gradle back in the 1.7.10 days, but I'm fairly new to it nowadays.  I'm trying to setup https://github.com/killjoy1221/TabbyChat-2/tree/1.15 in Eclipse.

Thanks for continuing to add to this mod on github!

In reply to killjoy1221:

Awesome.  Thanks for the reply.

Heyo,

I've been keeping track of this mod and seen some of the github builds you've been working on for it.  I just wanted to provide some encouragement, as this mod is very helpful keeping track of messages on MP servers and being able to have a personal record that goes back.  I wanted to thank you for updating this mod and your continued work on it.  For now, I will eagerly wait for the updated tabby chat.

Hey there

I wonder if we can set a Playername's Prefix as a TC2 chat filter please ? I mean to see a new tab [Event] when the member "[Event] Playername:" is talking or the filter detects only the "chat message/not prefix" ? I would like to use your mod because it looks clean aaaah dilemma.

Any plans for 1.13.2 (Rift) or 1.14 (Fabric) versions? Would strongly recommend since Forge is too slow to keep up-to-date.

Hi there

Thank you for this mod. How can I set the chat channels on my server please ? Have I to use another mod to do that ? (https://minecraft.curseforge.com/projects/chatcontrol). I have seen the folder "minecraft\liteconfig\common\TabbyChat2" but what I have to do ? Thank you in advance.

Edit: My god it is so complicated. There is tons of tutorial but 0 explain how to simply create a classic tab for TC2. Yes there is 1 million possibilities but it's really too much complicated. I don't need insane expression or filter or i don't know what things. I just need 1 new channel. Very sad.

In reply to Killjoy1221:

I realize Tabbychat2 cannot make a classic channel like I want. It filters only the words players are writting in the main chat and redirects the messages in the concerned channels. So I guess it is not possible to have a very classic chat with topics channels : 1 "game channel" to talk about the topic "game", 1 "sport channel" to talk about the topic "sport" etc. And when we click on the channels tabs we see what players write in this specific channel (no matter if they write the word game or sport). I wanna cry. You were my last hope.

In reply to Killjoy1221:

Thanks for your answer. I will take a look for a plugin solution yes. I could find utilities with TC2. I must setup my server first to see what I wanna do exactly lol

In reply to drakosoldier298:

 I also need this mod as a mod/admin on my server.