I'm making a browser based MMO (preferably strategy or at least with strategy/economy elements). But the catch is this would be my first game without resets and I don't know from which side to bite it I'm also not a big fan of non reset games so I don't know much about these as a player too...

The problems of "everlasting" model is legion, no point to even list them. Let's say for this for project I need it for immersion purpose and I'm aware of the troubles it brings. So, let's just focus on the "success stories"
What everlasting strategy-like games you know? Do you know of ones that work? Any ideas for strategy/economy mechanics where "rich gets richer" does not skyrocket too much?

Make it easy for rich players to kill each other the richer they get and add weapons wich dont have an immediate affect so the players can try to kill each other and both die :3

I'm making a browser based MMO (preferably strategy or at least with strategy/economy elements). But the catch is this would be my first game without resets and I don't know from which side to bite it I'm also not a big fan of non reset games so I don't know much about these as a player too...

The problems of "everlasting" model is legion, no point to even list them. Let's say for this for project I need it for immersion purpose and I'm aware of the troubles it brings. So, let's just focus on the "success stories"
What everlasting strategy-like games you know? Do you know of ones that work? Any ideas for strategy/economy mechanics where "rich gets richer" does not skyrocket too much?

The one that comes immediately to my mind will be Eve Online, I guess the reason why no one has yet to overwhelm the game is because the sheer impossibility of it (the game world is huge). Even with a strong alliance behind you it will take months to do it and if you start to steam roll across the universe with your all powerful army, other people can band together easily to oppose you.

I guess the most important mechanic here is co-existence and the ease of working together. This allows the players themselves to create a check and balance system - to prevent anyone among themselves from gaining too much power - that works well enough (in Eve Online context) that the developers never need to do anything about it.

Yes, Eve Online, wherever I ask they repeat the same sentence like a mantra

1) Any other neverending strategies except Eve Online?
2) What makes Eve Online so good?

All I can think of (not a game, a concept) is diminishing returns. In village/planet control mmo's the power one has is quadratic to the number of "stuff" they have. Example: Tribal Wars. Having one village against another person with one village is almost surely a draw. But two villages to one, even if that one is stronger than the two combined, the two may still win out because two allows for coordination. Even one extra domain may make a big difference. So all you have to do is the opposite of that diminishing returns.

Just somehow make it harder for someone to maintain an empire without it spontaneously falling apart. Remember, when cities and societies first started up, disease was everywhere and it killed many people. So one possible way for it to work is include a "disease factor" so the rich and mighty, while superior to the masses below in sheer might and power, are more vulnerable to suffer certain mishaps. Murphy's income tax -- pay $200 or 10%, the higher of the two. Richer people will need to pay more out, hence they can only expand their financial empire to certain soft limits.

Just think of how most games make it easy for the rich to get richer, and do the opposite.

Just think of how most games make it easy for the rich to get richer, and do the opposite.

I can't really do it There need to be both poor & rich gets richer (preferably the poor faster than the rich), that's the point of all strategy and economy games. If I go too far in that direction I will simply kill all progress for the rich...

Dimishing returns eventually turn into stagnation and lack of any progress (or maybe I should not worry about it and accept it? Not that I like it...)

The way I interpret "neverending" as opposed to having restarts, is making it more realistic, and not being able to just restart after making a simple mistake. And every capitalistic society does indeed suffer from recessions once in a while because of diminishing returns (kinda, sorta). The thing is, the deflation that comes with the recessions/depressions is what allows rich people to quickly fall to the bottom if they're not careful, and it makes way for new business/ allows the not-so-rich to become rich. Owning more would thus be both an asset and a liability, making it in a way, "neverending strategy". At the same time, those who excel at running a high power economy will not fall as easily, and may continue to prosper. In this way, it takes effort, time, and strategy to get to the top, as well as to stay on top.

The way I interpret "neverending" as opposed to having restarts, is making it more realistic, and not being able to just restart after making a simple mistake.

On the contrary. Neverending means the game is easier and less challenging. You just build things and accumulate more and more without losing it. The mood of such game is more relaxed (I think ).

In that case, I can't speak for Eve Online, but Runescape has something very similar to a "just build things and accumulate more and more without losing it". It has a bank system to keep possessions safe, as well as some money sinks that people can put money into to get unique (for cosmetic purposes, but otherwise useless) items. The fastest way to gain money is also the fastest way to lose money, which involves risking it in the grand exchange, which is another name for stock market. There are other ways to obtain money, which are slower, though less risky, and there is no limit to the amount of wealth one can have. There is, however, increasing differences between levels, meaning it's rather easy for one person to catch up to someone else who started a week earlier. Like this (the ordered pairs are (experience, level):
Person 1 Person 2
Day 7: (700,10) (0,1)
Day 8: (800,10) (100,7)
.
.
.
Day 14 (1400,11) (700,10)
Day 21 (2100,12) (1400,11)
Day 28 (2800,12) (2100,12)

So whereas Person 1 will always have more experience than Person 2, if the levels are spaced at some increasing difference (in the example, it's an exponential function), the newer people will be capable of catching up to the veterans, despite the initial differences in skill levels. This is somewhat equivalent to after two people play for a month, one week's difference between starting times won't make a significant difference, but more the difference being attributed to who is more dedicated. If person 2 is more dedicated and more strategic towards getting experience, it is fully possible that Person 2 can surpass Person 1.